the name margaret comes from her mum
I believe it comes from Margreta which is like Margaret
Megan is the Welsh variant of the name Margaret, ultimately ancient Greek in origin, meaning "pearl".
The nicknames Mog and Meg, which came from the name Margaret, gave rise to the rhymed forms Pog(gy) and Peg(gy). Margaret also has tons of other nicknames originating from it.
The Maori name for Margaret is Mareta.
Margaret Carnegie's birth name is Margaret Frances Carnegie.
Margaret Shelby's birth name is Margaret Reilly.
Margaret Bert's birth name is Margaret Birtwistle.
Margaret Fuller's birth name is Margaret Saunders.
Margaret Furse's birth name is Margaret Watts.
Margaret Spellings's birth name is Margaret Dudar.
Margaret Pellegrini's birth name is Margaret Williams.
Margaret Pemberton's birth name is Margaret McCoy.