I'm no expert and not a dog trainer . . . . . so be careful with the notes below.
We have an attached two car garage and a detached two car garage. . . . . . the attached garage, which has no vehicles, is where we have the dogs in the evening. They have two sofas, blankets, etc.
When Abby was a newly acquired puppy, I hauled a mattress in there and stayed with her the first two nights, then left her alone from then on.
The howling . . . .!!!
But it eventually ends.
Leave a ticking clock with your pup. Or maybe a radio turned on softly.
Give your pup a treat when you leave her alone so she associates the action with being a good thing. Say "bedtime" or some similar word so she comes to associate it with a routine.
These days our dogs run up to the garage door and can't wait to get inside because they know I have treats for them.
All of the above does have a caveat . . . . there is legitimately something called "separation anxiety" that can be quite profound and real in certain dogs.
I think its too early to apply it to your pup without engaging in some of the strategies above . . . . . its all very new for her and she doesn't know how she fits into your pack yet.
But one thing you don't want is your dog learning that if she howls, you'll come running.
Also, puppies are little terrorists.
Abby turns eight in a few weeks . . . . but there was a time . . . .
Cowperson