How do I know if I have been named in a will?

A close friend of mine separated from her husband 2 years ago and thinks her 2 boys may have been left in her late mother in laws will, the trouble is she doesn't have any contact with her separated husband. The husband also makes no contact with his sons but my friend is certain that their grandmother would have included them in a will before she passed away, we do not know the name of the solicitor who dealt with the will/ probate either, so how does my friend find out if her boys were named in the will?