My mother is a Baptist. She thinks it's great that Rocky and I are Catholic, she's always happy to go to Mass with us, she's been through RCIA but she won't convert. I think she feels it would be something of a betrayal to her parents memories.
I've spoken to four priests about Mama. One, the youngest, clearly didnt' want to distress me but clearly didn't want to say "don't worry about it". The others --one an old priest, the others were in their early 30s--- all told me not to be concerned. The church, they told me has taught since the 40s that Mama is part of the Holy Catholic Church because she is a Christian. She does not know this and obviously doesn't have the fullness of the Faith but what she does have is enough to get her to Heaven. I want to believe this but didn't Pope Leo (I forget which one) say that heretics shall not enter Heaven? I'm going to keep praying that if it is necessary for her salvation that Mama converts one day.