iTunes: How to transfer a music purchase between two Apple IDs?
Short answer
No, purchases can not be transferred between Apple IDs.
Alternative 1: Return/buy again
If you intended to use your mother's account to buy the album you may try to return the item using iTunes on your computer (Store > My Account...).
In case that you get a refund you can buy the album using the other Apple ID.
Alternative 2: iCloud Family Sharing
If you set up Family Sharing you are able to download purchases made by other members of your family that are a part of Family Sharing.