eta - cross-posted, but I think we essentially say the same thing. So you get it twice:
she tries push the bottle out with her tongue every time
I think MM covers method of starting a calf at the beginning of this thread, but just in case...
First couple of times feeding a calf you need to straddle its neck, so you've got full control of the head. Holding the bottle with one hand, give it a taste of the milk with the other then use that hand to clamp the calf's mouth shut
over the teat.
She may well sulk and try to pull back, but she shouldn't be able to push the teat out of her mouth. If she doesn't start sucking relax, both have a breather, try again with squirting the milk into her mouth first.
Typically, I offer the bottle to every calf shortly after separating from their mother and while most latch on straight away, it can take a few attempts before a *hungry* calf starts sucking the momma replacement. If I try three times and still no suckle (from a strong healthy calf) I presume it's not hungry and walk away... sometimes I'm wrong.
A new calf coming in with a full belly of colostrum - I wouldn't worry if it went 24 hours before accepting the next feed. Otherwise, twelve hours and if the calf still isn't sucking it's probably better to tube feed rather than leave her hungry.
Someone else may reccomend a shorter time. They're probably right.