What are my rights as sole owner of property

in 1996 i had several back surgeries and facing more, at the closing table when i bought my home paid in full by me. i ask my roommate at that time to go with me i told the attorney i wanted my roommate's name on the property because if i died during a surgery she would make sure my 2 children (under age at that time) would get the property when they were old enough. my roommate lived with me from 1996 to 2000, she has not payed anything on the taxes,insurance on the home nor any repairs nothing! her name is only on the tax owed each year,it is not on the deed.also the day at the closing table she did not sign her name to any documents of any kind. i recently called her to ask her to sign a quit claim that my children were of age and my wish was that my 2 children get the home when i died. my ex. roommate is refusing to sign the quit claim deed. i'm very worried, stressed and concerned my children will not get my home when i pass away.i know theres got to be a loop hole somewhere that i can have her name taken off. i'm only guessing but by her leaving the home wouldn't that be abandonment of some kind? please if anyone knows what i can do reply back. ty