Harriet Pitts Birth Certificate

This is my great-grandmother, Harriet Pitts, and the accompanying photo is of her parents, Robert & Clara Pitts nee Steel.

There is only one record for a Harriet Pitts born in Sheffield +/- 5 yrs of her known birthday, so I sent off for her birth certificate.
When it came, it recorded her mother's maiden name as Sharp!

But there are no marriages for a Pitts and Sharp - just Steel!
So, to try and resolve this, I've sent off for the birth certificate of Harriet's sister, Ada.
Can't wait till it arrives - will it say Steel or Sharp?
Could there be a skeleton?
The suspense is killing me lol!