It also helps enormously if there are 2 of you doing the bathing, for the first few times anyway, just until she gets used to it - one doing the holding, the other doing the showering and shampooing etc.
When Harry was little, I did him in the kitchen sink, in an old-fashioned washing up bowl, so he wouldn't slither around on the stainless steel.
Now he's older, he goes in the bath on 'his' bathmat, and just stands there while I shower him. It does get easier as they get older, and more used to it
Good luck! Sally + Harry x