Hello... Congrats on the upcoming new family members...Lol
Getting a new one will generally upset the pecking order of your current herd. If you have younger goats it'll probably be fine to have them together, but if all are approx the same size as the new momma you really should find a way to confine her till after she kids. There will be a lot of pushing and shoving and head butting and she could go into early labor or be injured and you could loose babies, momma or both.
Moving a pregnant goat at this point in pregnancy is very stressful on her so she'll need a place to settle in and get to know you. Fiascofarm.com has some awesome videos and pics of goats in labor and delivering kids. Check it if you get a chance, it helps to know what to expect and how and when to intervene.
And don't leave a water bucket where she can back up and drop a kid in it when she delivers. If you don't have a way to keep a bucket where that can't happen, then only put it in with her while you're there. Take it out at night.
Hope all this helps a bit and you can always pm me if you'd like.
Love talking goats!!!