Lump In breast

Hi, my name is Matthew.

My wife recently found a lump in her left breast, quite a large one  roughly the size of a walnut, over the Christmas break.

She has been to the doctor and has an appointment booked  soon.

Today she found another one in the right breast, alot smaller but still a lump and noticed that the first lump has shrunk in size to around half what it was.

She is really worried to have found another one. Is it normal for lumps to shrink in size and to have more than one.

Any advice would be great 

Thanks