I'm a 4th yr who will match in child neuro on Thursday and have recently finished interviewing for both peds and pedi-neuro residencies.
My PD advised applying to 6 while my advisor wanted me to apply to more (~10). I ended up submitting 13 applications for pediatrics and pediatric neurology and going on 10 interviews. From people I encountered on the interview trail, the range was 4 to 17 interviews (roughly).
Ultimately I think the answer to your question depends on two main factors:
1) The strength of your application (weaker app --> more interviews to be safe)
2) How much you know about the sort of program you are looking for before applying (e.g. size, location, academic vs. clinical, etc).
A separate question is how many pediatrics programs you want to apply for. To answer that you need to decide if you want to or can do you your peds residency at the same institution where you place to do your peds neuro residency. There are about 5 programs within the SF Match that allow you to apply ONLY through the SF Match and recieve acceptance to their affiliated peds program wihtout having to go through ERAS (this number will likely grow). Most others have a hand-shake deal with their affiliated peds program where acceptance for the later is generally pro forma following acceptance into the peds neuro program. Others give no special consideration to pedi neuro applicants for peds slots.
The general feeling in the field is that the match has INCREASED the profile of this residency and the quality of applicants so it is becoming more competative so you should keep that in mind if you plan on applying to top tier programs (e.g. Boston Children's, CHOP, Wash U...).
