What? No, that's flat our ridiculous. Children are attached to combs? Maybe a few insecure little kids but you're trying to tell me it's rampant enough that they have to tell people making reservations that?
No, that's utterly ridiculous. Stop apologizing for every dumb decision the company makes. JP - who knows more the you - just confirmed that they are doing because combs aren't always guaranteed.
My children have extremely thick hair. A standard comb wouldn't have a chance of getting through their hair without pulling or breaking. Chidren with thick curly hair have the hardest time, and sometimes a hair pick is the only answer. The same would hold true for different ethnic groups; many use special combs with extra wide teeth. Rather than ask a parent which type of hair their child has, they ask the parent to bring a comb. That way, the session can still continue regardless of hair type. I suspect the child will be given a "souvenir" comb, even if it isn't actually used.
There are also some children with very, very thin hair, and a standard comb would scratch their scalps, and make the experience uncomfortable.
Many people would be offended if they were asked "What sort of hair does your child have?" when booking a salon visit.
It could very well be, as JP stated, that they do, from time to time, and despite their best efforts, run out of combs. In that case, isn't it better to ask a parent to bring a comb- just in case - rather than cancel the session?
To answer the OP's question:
If this service had been available when my daughter was little, I would have definitely brought my own comb (and brush), without being asked, because of the reason stated above, and also because even in our own home, there was only one comb that she "liked" when she would let me use one; most of the time I only brushed her hair.
