My daughter fell and split her tongue open it's a nasty cut. I want to know will it heal properly, will her tongue go back to it's normal look?

Yes, but scar. Tongues usually heal really well unless the cut went all the way through at one of the edges leaving an unattached piece which should be stitched together pronto. Otherwise, it will be swollen for more than a month and she should only be eating baby foods and nothing hot or spicy. Dehydration can become a problem if she's not drinking. Milkshakes or ensure can provide nutrition.
Probably. Most lacerations (bad cuts) of the toung and gums tend to heal well. Once the initial bleeding is stopped, the tissues heal up well. If you have any concerns, please seek input from your pediatrician or an ear nose and throat (otolaryngologist) doctor.