Thank you for your question. Many of us have had the same issue, of the change in surname spelling. You can edit the name, by going to the Details page, where you see the Vital information, and give your reason. It might be helpful to put the name, as seen presently in the Vital section, as an alternate name in the Other Information section, especially if some documents use it.
The article link below may be useful.
Alice, is this an indexing question? Because if so, we index the surname for each person as it's written for each person. For example, if the child's surname is written Matthews and the parent's surname is written Mathew, you'd index Matthews for the child and Mathew for the parent. We don't correct person names in indexing. Besides, how would you know if it's the child's or the parent's name that's correct?