iTunes Family Purchases after purchaser dies

I am the creator of my iTunes family with two other members. My mom was one and has passed. She has over 40 dollars of iTunes credit (from gift cards) which is not directly transferrable. I frequently share music downloaded with MY funds with the family members. In order not to lose her funds, I know I can purchase music with her appleid and then download that to my devices. The question is, if I remove her apple ID from my family, with the music files I downloaded with her ID still work? If not, I can just leave her account 'open' forever. Just trying to reclaim her account balance.