As Jordan relates in a flashback, Daisy almost changed her mind about marrying Tom after receiving a letter from Gatsby (an earlier relationship of hers, discussed below), but eventually went through with the ceremony "without so much as a shiver" (4.142).
Daisy appeared quite in love when they first got married, but the realities of the marriage, including Tom's multiple affairs, have worn on her. Tom even cheated on her soon after their honeymoon, according to Jordan: "It was touching to see them together—it made you laugh in a hushed, fascinated way. That was in August. A week after I left Santa Barbara Tom ran into a wagon on the Ventura road one night and ripped a front wheel off his car. The girl who was with him got into the papers too because her arm was broken—she was one of the chambermaids in the Santa Barbara Hotel" (1.143).
if that helps//prepscholar