Too much partying Bella?! Oh no!! Well, if I celebrated my dogs' birthdays, I would give them more than half a finger of steak too! It probably was the steak though. Did she also eat a cake pop or something else also? I would be comfortable waiting until Monday for an x-Ray if it was Winnie.
Anytime my dogs vomit (unless their stomachs are empty), they vomit whole kibble because they just gobble their food without chewing it.
Let us know how she's doing--sweet little Bella!