It's also up to you to check out the quality of their previous work. Good photographers have folios and albums to show you when you book, and there is no harm asking if they have actual qualifications.

My SIL did this - bought herself a noice camera, took a few decent shots of her kids and decided she must therefore be a professional. Advertised her services and everything. She asked me if I wanted some shots of DD when she was tiny (for her 'folio' too of course) - they were bloody appalling, and it was then I realised she had no idea what she was doing apart from aiming her lens in the general direction of the subject and pressing the button.

Light? Depth of field? No idea - she hadn't even done a basic course at the local tafe ffs....
I hope you were honest with her, Lulu