Struggling

I (42 M) am married to my second wife and she has a 14 year old non verbal autistic son. When we first started dating she thought it may be an issue for me but it really wasn’t as my older brother is also autistic. Her son is very sweet and has the normal autistic stims and things that’s no problem. My issue is that I feel we should be doing more to help him progress than what we are doing. One thing is his iPads, yes he has three and he regularly has two at a time. He is on YouTube nonstop and will listen to the same video over and over and slow down the speed and it drives me nuts sometimes and it even upsets him to the point where we tell him to watch something else or we will swap iPads out. I’m not a fan of the constant iPad but he is also not my kid and I don’t want to step on her toes. When we I bring up doing something new to help him she gets defensive and says I’m making her feel like a bad mother. I’ve assured her that’s not what I’m saying and I’m careful in the way I say it.

I also have three kids of my own who live with us half the time and whenever I mention something about helping her son she says something about mine and what they do. It’s not helping the situation and I don’t want to be 75 years old and still helping him wipe his butt or take a shower. I feel if we spent more time doing these over and over he would benefit but it seems like she just wants to let the iPad occupy his time.

Just venting and also looking for some insight if you have it. Thanks!