The journalist and presenter tied the knot with Cohen, the father of her 4-month-old son Astala, at the St Mary Magdalene and St Lawrence Church in Kent, where Yates's marriage to Sir Bob Geldof and her funeral in 2000 were held.
"I feel her presence all the time but especially today," Peaches told Hello. "Mum loved family celebrations and she would adore Tom and the fact that we've married here.
"I know that she is watching over me and feeling so happy for us."
Peaches's musician father was present at the ceremony, while her siblings Fifi, Pixie and Tyger were among the seven bridesmaids.
Speaking about the importance of family, the 23-year-old stated: "I know it might seem old-fashioned to some people but I love that Astala will know that his parents are together and have taken the vows we've taken today.
"I've married the most wonderful man who I know loves me beyond anything, through all my faults."
Geldof announced her engagement to Cohen in December 2011.