You didn’t mention what kind of phone she’s using. If she’s on an iPhone you can add her AppleID under your family account and you can have full control under the “family” screen time settings as to which apps she can use, when, and for how long. For example you can block contacts completely, block texting at certain times of the day, allow communication with only certain contacts during certain hours of the day. It’s actually insanely impressive the level of control and customization you can have over their access on their phone, and you can also lock it so they can’t sign out of their iCloud account on that phone to get around any of the restrictions.
I’m not super familiar with Android devices, but you can lock settings down in much the same way with Google’s “Family Link” app as well.
As far as restricting certain services through public mobile, you can’t. But if you wanted her to NEVER be able to text, you could always get a pay-as-you-go voice only sim for her phone.
I hope this helps!
