Transferring Data from old 3DS to new 3DS XL with pre-installed data

Hello,

I have a very unique situation and I'm wondering if there is a way to do this.

I had an old 3DS that I handed down to my daughter.  I got a new 3DS XL Mario Dream Team Bundle.

My daughter got the new Kirby TD game and is already playing on my old 3DS.

What I would like to know is if there is a way to transfer my old save data and downloaded games to the new 3DS XL without erasing the pre-installed data.

Also, I would NOT like the data to be erased from the old 3DS, so my daughter does not have to restart Kirby TD.

Thank you for your time!

-Dan