As iPhone/iPad devices tend to be more expense to buy compared to Android devices, would you agree that Android users would tend to be younger? (Parents buying cheaper phones for their kids…?)
For example, a kids cartoon platform game would be do better on the Google Play store and a City Builder strategy game on iOS?
Just a thought…
I would agree that adult iOS users tend to be more female. At least in Seattle. Also, I believe the Samsung Galaxy S6 edge costs more than a similar spec iPhone 6S.
On the low end, sure they are less expensive and probably kids have them more for that reason. Not sure though.
Why not Amazon’s Marketplace? Their new affordable tablet has great features and performance for the price. There are videos up that show various games - both 2D and 3D - running on the tablet. I feel like those tablets will be the ones most kids will end up with.
I’m not a statistician, and I’m also not always “in the now”, so take my opinion with a grain of salt. But, my thoughts would actually be the reverse, Apple products seem to be more trendy and kids would want the more trendy phone. Androids seem to draw more tech savvy people, which I would usually put into the adult category.
Monetization is pretty across the board better on ios (about 5x per capita). It depends on what you mean by doing well. If you are selling or looking for downloads. If you are selling, (or iap), targeting the inexpensive devices is not a winning strategy, if a person is buying an inexpensive phone, they are unlikely to spend money on a game. But also important to remember is that “Andrioid” is huge wide market. It has expensive high-end devices, and a butt-load of low-end, old devices. It is also widely used in developing countries.
Do both.
Here are some numbers from 2 years ago. http://www.emarketer.com/Article/US-Smartphone-OS-Race-Still-Close-Men-Younger-Users-Favor-Android/1009961
There are probably some new numbers out there somewhere. Not sense in guessing, as people have put a lot of effort into studies. 
Parents I know don’t buy cheap devices for there kids. The kids simply get the old device the parents are done with.
But this is all anecdotal. As @zombiegorilla said there are plenty of studies on the topic.
I wonder if Amazon’s Fire OS is lumped in with the Android numbers. Technically it’s Android under the hood, but it may identify itself differently.