As she wants to live with you in your room ,it is not a punishable in open eye of court.
You can go live in relationship. Since last two years you noticed her change in nature so you also want to live in with her. You are also planning to live with her.
I advice as under:
Do not go for immediate Marriage with her.
You enter into Friendship Agreement/ Live -in relationship for a year, as a contract, thereby mentioning the fact you mentioned here.
She should not have any property rights ect, right now.
Nature changed? or trying to trap you?? You may misunderstand her tricks, if any to enter into your life or your room?
So for safety of your life, and property, you should do this. Marriage include burden of maintenance and residence etc., and as she failed to get under 498a, marriage was nullified, Suppose she want to get it legally by becoming your legally wedded wife??
"SAFETY FIRST" READ WHAT CHANAKYA SAID FOR WOMEN *NEGATVES FOR THEIR RELIABILITY AND TRUSTWORTHINESS*" So at least for a year, Live together, but do not give all rights of a wife. Do not marry fore one year. Enjoy her & her relationship on probation basis.
After a year, and in case you have a baby through her, marry her. SAFETY FIRST