Hope everything settles for you. My husband and I watch your story from beginning up until now...really it looks like a TV series!!!! HAHA write a book on it and COPYWRITE it!!!
Anyway, we both think after BB is born, your 99 and that b6 will not move out, it's actually better to move BEFORE bb is born. There's so much to do after BB is born, it'd be a big hassle to move afterwards.
You might want to talk with your husband on this, because if they move now, they can settle down to get ready for BB and set up the new place for BB. Now the B6 is only pregnant and other people can MOVE everything for her( and MOVE HER), she doesn't have to do anything, but after BB is born, she or your 99 will need to take care of the BB, who can move and pack??? and says the smell in the new house is not good, the chinese fung shu is not good to move after...they will just have move excusesssss !!!!
I am not being considerate to them, i don't really care about them but you. however in this case, asking them to move after will be more difficult (we think) so it is just a suggestion and something you and your husband might want to consider~
You take care and stay healthy, your lovely BB will come naturally
Perhaps, the best solution is to sell the property and share the proceeds in agreed terms. Then it is clear cut and problem free. Once your hubby remains as the owner, they can play whatever game.