Actually if you watched all the episodes so far Kallie was unaware that Paul had any kids at all. She didn't know until they had already agreed that she was going to move down there and live with him. It made her think twice about going down there as well. Personally I want to know right off the bat if a guy has kids or not because I feel thats a big thing that shouldn't be hidden at all. Some people prefer to date someone who doesn't have kids. I am not picky about it but if a guy can't tell me straight up he has a kid or kids, then I consider that lying and won't continue anything further.
So not all of the girls knew the guys had kids.
I get what your saying about Valene though she can be kinda rude. She is not used to this at all and I think that she only came because she had feel wicked hard for Mike and kinda put the whole fact he had a kid thing to the side. That didn't really bug her much until she actually got there. Her friend even told her that that was going to happen that it would be hard for them to have alone time.
Jake there is something way off about him that I don't think anyone but him knows about. I think he is sneaking around and figured by meeting Amy and bringing her to live with him it would give him more of a chance to sneak out on his own. I have a feeling she is going to catch on quick and leave soon. He didn't even have the nerve to tell her that he had surgery so he couldn't have more kids, which is something he should have said when they started talking. I believe she would like to have kids of her own im sure.
Also the fact that sarah never told Jason she had never had a real relationship before was a big no no. She should have been honest with him about that from the beginning because it is clear that that is a big turn off for Jason, even more so since he has 2 grown daughters.
Lastly I think that Paul's kids shouldn't be saying things to Kallie about their dad wanting someone to do the cooking and the cleaning and the motherly things. That is just setting him up for disaster and seems to me like maybe that is what he is really looking for.