Enigma,

It is a pretty common thing for childcare workers to deal with having children who speak very little or no english. And to deal with children who are (quite understandably) very attached to their mumma. As the other girls have said it is a great idea if you could take her to the centre for a few visits before she actually starts, and then when she does begin if you can leave her fo short days and slowly increase them. Try to build a relationship between her and the carers who will be with her all day while you are there. And as for her not being able to speak english, she will pick it up very quickly. Make up a list with some common easy to use phrases on it for the carers, like 'sit down, stop crying, toilet, drink, eat, come here, mummy/daddy will be back soon, sleep time, etc....) Occaisionally with young children, they will get a bit mixed up with the two languages, but they will get the hang of it very quickly. Perhaps you could talk to her in english when it is just the two of you, like when you're in the car, or when your'e shopping or something before she starts childcare, so that it isn't completely foreign to her. When she does start though it is s good idea to only talk polish to her at home though, because then she will learn that childcare is for english and home is for polish.
Good luck.