Your MIL sounds fab. Things change all the time, and whilst your mums attitude to looking after your son is not the same as yours, by the time he is a bit older it may seem great. Alos she is working ful time with a 6 year old? sounds pretty generous to even think of offering to babysit this special weekend. I think you have to think long term, you will fell sensitive about your history at the moment, having a second baby sounds like it will be tricky, but in the long term you are lucky that she has offered- albeit on terms you don't like, but when your oldest is say 3, and hopefully eating and sleeping in a normal bed then that is when she will come into her own. Play the long game, you are lucky to have a mum and MIL within 1.5 hours.Please stay in touch with her- maybe you can send her a weekly / monthly e mail to keep in touch.