Thank you everyone, she is home and fine, apart from a big bald patch on her chest. They have sent the sample off and will ring me in about 3-4 days with the result. I will let you know as soon as I hear.
She didn't need to have any sedation, just a local anaesthetic injection. It was awful leaving her, she was really shaking when the nurse carried her away, so straight from collecting her we took her to a cafe we know and they cooked her a sausage, which helped take her mind off her trauma. She has been a lovely walk in the sunshine and is now fast asleep on the bed.
Thanks again to everyone for your kind comments, please keep all fingers crossed that the lump turns out to be nothing.