Well, my daughter was like that.
She was just a bad waker-upper.
Nothing wrong with her.
My friends kids were like that too, when younger.
My daughter has outgrown it.
Even some Adults wake up grumpy.
Or, kids/babies wake up like that because they are still tired, or were waken up.
Also, sometimes if you let them be, the baby/child may just go back to sleep.
If you don't interrupt them.
My son would do that during naps. He'd nap well. Then wake/make cries about an hour later. Then go back to sleep. It was his cycle.
And his way.
If I swooped in and interfered with him, he got GRUMPY!
My Mom, was such a morning person. SO perky and chatty when she woke up. SO irritating to the rest of us.
We liked quiet when we woke up. AND to wake up on our own, in our own space and NOT be interacted with as SOON as waking up.
Took her YEARS to realize that. That not everyone wakes up like her.
Babies/kids also get 'separation anxiety' at various ages. Not only when they are a baby.
Does your baby have a "Lovey?"
Or a comfort item??
If not, then let her have one.