REF. post upthread that said Kendra was rooting for Kirstie. I also heard that and I think that Kendra can relate to Kirstie since Kirstie has been a single mom for awhile. Kendra's mom raised Kendra and her brother alone and Kendra feels admiration for mother's who do that. (I don't know the details of Kirstie's children's fathers, except they have not been seen around a lot.)
Also, Kirstie has suffered with her weight issues and Kendra suffered that too as it took her awhile to lose the baby weight after having little Hank. She took that really hard. So, I think that she really relates to Kirstie.
I hope Kirstie really pulls out a great number tonight! If she goes home, I don't think I'll continue to watch the show. Not to be mean, but I don't think it will be very interesting.