Need help with 13 year old inappropriate texts.

Hi guys. I’m needing some advice. So I have a 13 year old stepdaughter. She has an iPhone under her moms phone plan. She used to be on ours but our rules were too strict for her so she asked her mom to take over. That was about 8 months ago.

So less than a year ago we had done a spot check (asking her for her phone on the spot so she can’t delete anything) and found very inappropriate texts with another boy her age (they were 12 at the time) - I’m talking butt pictures and talking about sex. We confronted her about it, let her mom know, and took the phone for a month. This was not the first time we found messages like this (in 5th grade another mom called me to let us know she had found messages on her sons phone between them). Shortly after this was when she was switched to her moms plan. At this same time she also went to go live with her mom full time for 6 months until she decided she wanted to go back to 50/50 about 2 months ago.

So her mom found similar messages this past weekend with multiple boys and confronted my stepdaughter about it. My stepdaughter went on to say she’s insecure so she does it to get attention from boys, as well as she’s depressed and suicidal. I know these are things never to take lightly, but I’m worried she’s using it as a way of getting out of trouble a little easier.

So it’s been a week and she already has her phone back. My husband and I’s first instinct is to switch her to a flip phone with no camera since this has been an ongoing issue. And if her mom won’t do that, tell her she is not allowed to have the phone when she’s at our house (our reasoning for this is because we live in a very walkable community with her peers where she can meet up with boys at any time where her mom lives a little further away).

Does this seem reasonable? This whole blended family thing is rough and tough to navigate. I want her to be safe and protected. Any advice would be greatly appreciated.

** UPDATE: She is seeing a therapist