Looking for advice on a mixer to combine 2 roll up drum pads and a smart phone.

I am not a drummer but my 26 year old goddaughter has played drums since she was about 10. When she was 14 I bought her a $2000 DW set that her mother probably added another $1000 to and I thought it would be something she would have for decades. But she encountered problems in life along the way, not all her fault, and that DW set and others are long gone.
Combine those with having trouble finding a place to live much less a place to simply be able to play has been a problem as well. She currently has a couple of those roll-up drum pads which she enjoys. I ordered 1 for her and unknown to both of us her mother ordered one as well.

Here is the question: is there a simple mixer or something that she could plug in both drum pads (she can tune the drums and cymbals differently) along with her smart phone so she can play music to drum to and then listen on her headphones? They all would connect with a headphone type jack. This might sound kind of rinky dink to some here but it would mean a lot to her to be able to do this because drumming is important to her life.

Thanks in advance for any advice or responses.

just a 4 channel mixing desk that would be the best option ..go cheap arse brands like behringer

Just sent you a PM, with some links to check out.