After all, leveling up with her skills will be useful exp to give to permanent characters.

personally i just have her use burn/burnflame in encounters to give fire levels to rapp later, but you have more options than that (very old route gave her water/earth to give to feena later etc.)

The thing about transferring magic levels in general is that you only transfer 1/3rd of the EXP to the new character, so there's a decent chance that investing time into leveling the original character is just going to be a waste.