Putting music onto iPhone from a different Apple ID?

I bought new music with my mom's Apple ID and I want to put them onto my iPhone. When I go to download them from her Apple ID "Purchased", I get a message that says: "This Device Is Already Associated With An Apple ID. If you download past purchases with your Apple ID, you cannot auto-download or download past purchases with another Apple ID for 90 days." What happens if I click 'Transfer'? Will I still be able to download music on my own Apple ID account?