woah, woah, woah.. do not jump the gun here..
Have you actually been to these photo shoots, if so what do they in tail?
I know plenty of mothers who are obsessed by their kids and treat them like prize objects, taking snaps whenever the chance arises.. she could just be one of those obsessed mothers or there could be something a little more sinister too it all... go with her next time and if you do suspect anything out of the ordinary then you have to report it!
Until then hold your judgment otherwise you could be opening up a whole can of worms!
Good luck