We notice something common to relationships in Virginia Woolf and Graham Swift's writings: most times they are unhappy. What is more, relationships described in Swift's writings may be regarded as mirroring Woolf's own with Leonard.
Marriage was something Virginia and Vanessa didn't wish for but knew that one day it would have to happen, similar to the attitude of Clarissa and Sally in Mrs. Dalloway. In The Voyage Out, Rachel dies before she gets into marriage. In Night and Day, Woolf examines several issues related to marriage: if love and marriage can coexist, and if marriage is necessary for happiness. Questions, dilemmas and examples of unhappy marriages are also found in Swift, especially in The Sweetshop Owner, where marriage is seen as a bargain. It's something Irene can't escape and, most sadly, something she is forced into. She tries to get through as well as she can and yet both she and her husband end up unhappy.
Woolf mentions the problem of a lost identity which comes together with marriage, in The Waves, where Rhoda says, related to this subject: "Identity failed me". Clarissa in Mrs Dalloway refuses to marry Peter because he wants to share everything, while Richard allows her more freedom, and she does so in turn. Leonard allowed (and wished for) Virginia to continue to write after their marriage.
A solution to the problems of marriage may be not getting married at all. Such examples are offered in Woolf's The Years where Eleanor never marries and neither does Rose. Their father had a mistress even while their mother was on her deathbed.
Inability to love, as a consequence of traumatic events or a sensitivity which is not understood by the other person (where specified in novels), appears as a common theme in both authors. This is the case of Irene Chapman in Swift's The Sweetshop Owner, Rachel Vinrace's in Woolf's The Voyage Out.
There may also be unhappiness related to the couple members' growing distant to one another. An example is the marriage of the Dalloways in Woolf's "Mrs Dalloway" (at some point she mentions that they no longer share a bed and she also feels at some other point left alone and a bit jealous on a lady her husband has lunch with) or the temporary situation in Swift's Shuttlecock.
The couples in Swift's "The Sweetshop Owner" and in Ever After may echo Virginia Woolf's and Leonard's relationship and image as a couple. She, a beautiful, important woman (famous even in "Ever After" as she is an actress) and he, a rather insignificant man, almost always in her shadow.
Mental problems come into the relationships of characters in both Woolf and Swift. In Mrs Dalloway, there is the couple Septimus-Rezia, where he is affected by shell-shock and unable to feel or to distinguish, at some point, reality from fantasy. In Swift's Waterland, there is Mary who can no longer have children because of an abortion in her youth and she steals a child from someone in the supermarket and says that God has given it to her.
Interestingly, Mary echoes Virginia's not being allowed to have a child by her doctors and also by Leonard due to her mental problems. Irene, however, in spite of her past, manages to offer her husband a baby, even if out of a sense of duty.
There are misunderstandings between husband and wife, as in Swift's Shuttlecock which may, however, be only temporary. Same with misunderstandings between parents and children. (Like in To the Lighthouse, in Shuttlecock the boy has certain problems with the father at some point in his life.) After all, these are something normal in any relationship.
Swift also brings together couples where there are no misunderstandings between husband and wife, as in Tomorrow, yet they have other problems to sort out (such as explaining to their twins how they were artificially conceived).
Woolf herself, surprisingly, portrays a happy relationship in Flush: A Biography. Elizabeth Barrett-Browning suffers from a mysterious illness which has her confined. She is in fact a "prisoner" both of her illness and of the authority of her father. However, once she meets the poet Robert Browning she begins to get better. She gains her appetite and finally when she runs away with him to Italy she becomes a normal, healthy person. In this case, love and understanding helps in the case of an illness. Probably this could have been Virginia's own situation, if she were offered more understanding by her husband Leonard, if he were a good psychologist. Or if he had not trusted so much the so-called specialists who only did more harm than good to her.
Another exemplary couple are the Ramsays in To the Lighthouse, modelled on Woolf's parents. However, he is more rational and he is more intuitive.
In Swift's To the Lighthouse, George Webb is left by his wife, yet he gets a chance with Sarah, his client. However, Sarah herself had been unhappy, as her husband fell in love with a Croatian refugee she herself offered to shelter in their house.
Other examples of unhappy families in Swift are to be found in his novel Out of this World, where Sophie is in therapy in order to solve the problematic relationship with her father who had decided to start a relationship with a younger woman. More problems within the family are to be found there, however.
Swift's short stories also offer examples of troubled couple relationships. In Seraglio the couple is in conflict, and also in Learning to Swim, where the two parents fight with one another and include the boy in their fight. Their son finally swims away from them both.
What would be the solutions to unhappiness and conflict in relationships? In Shuttlecock, Prentis finds getting back in touch with nature a solution, after understanding that not even those whom we see as heroes are not perfect (the case of his own father, who may not have been in fact a war hero). With Woolf, probably, as presented in Flush, love and understanding could have been a solution. Maybe like this she would have had enough courage to tell him all about her past experiences with her half-brothers and he would have helped her.
Woolf rests upon autobiographical material in portraying most relationships, while Swift mentions that he has had a happy childhood and he is in a happy relationship with his wife.

References
Poole, Roger. 1978. The Unknown Virginia Woolf, Cambridge University Press.
Swift, Graham. 1980. The Sweet Shop Owner, Allen Lane, London.
Swift, Graham. 1981. Shuttlecock, Allen Lane, London.
Swift, Graham. 1982. Learning to Swim and Other Stories, London Magazine Editions, London.
Swift, Graham. 1983. Waterland, Heinemann, London.
Swift, Graham. 1988. Out of this World, Viking, London.
Swift, Graham. 1992. Ever After, Picador, London.
Swift, Graham. 2003. The Light of Day, Hamish Hamilton, London.
Swift, Graham. 2007. Tomorrow, Picador, London.
Woolf, Virginia. 1998. Flush: A Biography, Oxford University Press, Oxford.
Woolf, Virginia. 2001. Night and Day, Transaction Publishers, New Brunswich, New Jersey.
Woolf, Virginia. 2003. Mrs Dalloway, CRW Publishing Limited, London.
Woolf, Virginia. 2004. The Voyage Out, Barnes & Noble, New York.
Woolf, Virginia. 2005. The Waves, CRW Publishing Limited, London.
Woolf, Virginia. 2006. Oxford University Press, Oxford.
Woolf, Virginia. 2008. The Years, Harcourt.