The way it reads, Holli, your partner's getting cold feet about moving in together, whether married or not.
The only alternative seems for YOU to provide a home, let her sell her own place and keep the money in the bank in case of future "eventualities".
You've offered to do everything you can, and it seems that the possibility of losing her house means more to her than being in love and wanting to settle down with you. I hope that's not the case, but if you re-read your post, that's what it sounds like.
As Mrs. Pegasus says, suggest seeing if a solicitor can draw anything up, and if your partner still objects - it looks like a no-no.