How do I get my texts to stop going to my sisters phone?

We both have iPhone 7 s and use our moms apple ID, but we keep getting each others texts and that never used to happen before, does anyone know how to fix it?

I'm using a version before iOS 11 so it might be different, but…

Try going to settings > messages > send and receive

Does it send and receive from the Apple ID? If it does, change it to your phone number

Get separate Apple IDs.

Ya get another account… Or turn off texts

In settings, you can turn on our off if all parties sharing the same I'd, get each other's messages and texts. Check both phones. DH and I had this problem after an update. Solved in seconds.