Tracking kids phones

I agree with Astral especially with the sentence about how your SIL has suffered a loss and may be more anxious than some.
Dont take it to heart. I'm sure it's not an indication of how he feels about your care of GD.
Condolences on the death of your daughter

I agree with everyone it’s the safe thing to do nowadays. Sorry for the loss of your daughter.

I'm sorry for your loss

I think it is OK to track childrens phones until they say it isn't. But only for emergencies, not to follow their every move. They need to know its just a way to find them in an emergency, using it as surevelance is wrong. There are teens out there getting messages from family members "why are you there, you should be here!“ and if you use tracking to watch their every move, they just get an app that hacks the tracker and says they are at A when they are really at Z. That's even worse if they do go missing.

I would not have this app, I'd rather teach my children how to handle a bad situation and how to stay safe than send the message I don't trust them but that's a personal opinion.

It's not my place to question another parents motives for doing it because they could be good. In this instance, your son in law has experienced a loss and may have more anxiety than some.

Try not to worry about it unless it becomes an issue for your grandchild.

Having a tracker app in a 9 year olds phone is completely normal. And responsibile.

My DDs track my DGCs! So they will be tracked when they are with us too! It is fairly common practice.

Condolences for the loss of your D Geegee. I think MissA is right and the tracker on your GD's 'phone is there all the time, not just when she's with you.

Your ex s.i.l. is clearly a loving and sensible father so don't take it personally.

I think it's fairly normal now
Parents can even track what their DC have for school lunch.

I'm sorry too, you all sound as if you're doing a good job with this little girl who lost her mum at such a young age.

I would imagine the phone tracker is on all the time, not just when she is with you?
I would try not to let it interfere with anything that you do.
I'm sorry for the loss of your daughter.