There is also that Oda has drawn her twice now and incorporated the number 56 into her design both times. A 5 in her ear and a 6 in her hair. She was also revealed in chapter 1156. 56 is associated with Luffy because it means Go (5) and Mu (6). Oda has drawn Luffy several times wearing that number as well. Of course we won't know for sure unless Oda confirms this himself but the number association to me is the biggest hint that Tritoma may be Luffy's mom.
EDIT: Just to add another interesting wrinkle is it would explain why Kuma would send Luffy to Amazon Lily of all places.
