Yes, you will be able to blend her current form into her new monster form! Over time, she'll end up looking more like her monster form should, but she can keep the cosmetic flower-growing if you'd like.

As far as the regeneration, that would be nerfed. She can heal quicker than a non-Monster, especially since Monsters heal quicker in general, but it will be slower than she's used to, and regenerating whole limbs may require extra magical intervention.