Okay, not technically fully inexperienced but I think I'm inexperienced where it counts.

Background: I have an 8 year GSD mix (her picture is what's attached). I've had a few family dogs throughout my life but she was MY first dog. I had responded to a friend of mine's post about needing to get her 3 year old "small shepherd mix" a new home as she already had too many dogs. I'm so unbelievably un-authoritarian, most of my friends with dogs said I was terrible with them as I kind of let them do whatever they wanted lol. She told me this dog would be perfect for me and she couldn't have been more correct! I took home a 75 lb dog who is so loyal and smart and amazing I just talk to her and she listens. It made me a total convert to the breed, but I also know I did *none of the hard work* in terms of training & dealing with puppyhood/adolescence.

Current situation: my mother lives with me, MY 2 YEAR OLD, and my husband. She is.... impulsive? Difficult? Ridiculous? All of the above. Anyways, 9 pm last night she went to the store and came home with a 9 month old gsd/malinois mix a homeless man gave her. Breed type was what he claimed, she (the dog) gives long hair gsd vibes with I don't know what else. I haven't taken a picture yet otherwise I'd post.

What on earth do I do? How do you handle a 9 month old one of these to ensure my 2 year old stays safe?! Of course this dog seems nice in the first 5 minutes of having a home but I know she's still young. My normally very mellow dog is a little miffed (she's much more comfortable with small dogs than dogs her own size) and was given no time before this brand new dog walked in her house. I don't know if I'm looking for validation that this was nuts or just advice on the best way to make this sudden addition transition smoothly 🫠 

Inexperienced GSD owner advice (I suddenly have a 9 month old dog in my home)