Piano tutoring is not something that is regulated by Ofsted or professional bodies so you may find that he/she may not have CRB checks if he/she is a private tutor.
If you just want your child to learn as a hobby to begin with rather than training her for music college then where the tutor went and what degree they have does not matter at this stage. You may wish to consider the following:
Is the tutor friendly and professional?
What background do they have? Experience is more important than qualifications in my opinion. That said, do they have grade 8 at a minimum? I personally would hesitate to accept someone who wasn't grade 8 standard or equivalent. If you want to find out what the acronyms mean wrt music qualifications then the following forum might be useful.
ABRSM
Do they relate well with children? Some piano teachers in my experience are reluctant to take on children under the age of 7 but others may be willing and if she practises regularly and manages to concentrate during the lesson then she will make a good pupil.
What are their exam results like? 6 is a bit young to already think about exams and there is no rush to do them, the tutor will know when she's ready.
Have you tried asking anyone from school whose child is learning the piano?
You can try posting on the ABRSM under the parents or even the teachers section. I think that section is busier so you'll get a quicker response from there.
Hope this helps. Good luck with finding a tutor.