Looking for advice and ideas.

I've been divorced for 5 years. Everything eventually came up aces. Bought a house 4 years ago. Interest rate is very low so can't refinance ever. I want to stay in this house forever.

My girlfriend of 3 years moved in last year. She pays rent (low amount for a sick house), helps with groceries, and is proving to be an excellent stepmom (she has no kids but wants them). We are mid 30s. She is a very hard worker but limited earning potential. Makes about $50k give or take mostly tips.

No complaints about the relationship at all. I golf all the time and we have a very happy life. My state has common law marriage by a different name.

She has cash savings and I need to find a way to protect my house and retirement (already burned in divorce round 1). I think she deserves a path to some home equity, especially if we get married and have a kid. Otoh, I don't want to refinance the house if we breakup. The house has a good amount of equity already.

What does the Reddit hive mind have to say? Pre-nup with my house and retirement off limits? Reduce her rent on condition she starts an IRA? Other creative ideas?

Spare me the don't get married chatter as is it is something I'm considering with eyes wide open. I already sowed my wild oats and had my rebound relationships.

Thanks.