If somebody was blind and somebody made my mom sign pension papers without her knowledge, is that fraud?

If the somebody was your mom and she signed pension papers without knowing what she was signing, it may be fraud, theft, etc. Blind people sign things all the time when they are explained to them. If no one was there it explain the document or explained it incorrectly, there may be fraud or enough to take back her signature. Call the police and hire an attorney to petition to rescind (undo) whatever it is she signed if she never agreed to it.