I'm single and in my 40s and got Kyleigh 16 months ago. I have lots of experience with dogs, and my "dream dog" is the GSD.
As a first time GSD owner, I was rudely awoken a number of times with Kyleigh. She did things I haven't seen in other dogs / puppies.
The landshark phase / biting / teething ... it CAN be over the top for someone. Especially if you have children - and ages 2 and 4 are too young to be dealing with that (not that I expect you to have them "deal" with it). But just managing that "phase" as well as two small children will require extraordinary effort - do you cage the dog all the time? Or the kids? (just kidding!)
If the puppy is not managed 100% of the time during the teething / landshark phase, your children might become afraid of the dog.
Kyleigh demanded (and yes, I mean DEMANDED) my full attention until she was about 8 months old. If I wasn't working with her (training, playing, etc.) She was in her crate (thankfully she settled in her crate admirably). I had to "teach" her to have an off switch. I had her leash attached to me for 4 months while we were in the house. This taught her to follow me, respect my space and I could watch her and make sure she didn't chew / eat anything she wasn't supposed to.
BUT ... she would NOT settle for longer periods that 15-20 minutes unless she was in her crate. This is what I had to teach her ... and it doesn't happen over night.
Some puppies are more demanding than others. You might get lucky and get a mellow puppy, but on the other hand, you might get one that DEMANDS your attention like Kyleigh did, and I had to teach her to relax.
Kyleigh calmed down around a year old. I exercised her both physically and mentally for hours ... and she was still ready to rock and roll at the drop of a hat.
Personally, with my knowledge of dogs and my very recent experience of raising a GSD puppy, I would go with an adult GSD from a rescue, or even a retired dog from a breeder. With two children in the house, you will simply be adding another child to the picture ... but one you can't have a discussion with!
Just my two cents!! Good luck with your decision
Marion’s Zoo-Kyleigh, Raylan-cat, Echo-TAG,