Hi David,
There is an Aldborough baptism record for a Margaret Ripley on 10 July 1602, father George Ripley. It's a possibility. I agree that she likely came from the large Ripley family from the area around Ripley and Rippon. There was a George Ripley from a couple of centuries earlier who was a famous alchemist(!)
The Alice Plumpton does have a lot of useful family data. In combining it with the Knaresborough baptism records (which seems to be this Plompton branch's local church) I believe Robert and Alice's children were:
Thomas, baptized 8 Sep 1588
Dorothy, baptized 10 May 1595
Ellen (Elena), baptized 1 Apr 1599
Edward (Edmund), baptized 14 Jul 1602
Henry,
No baptism record I can find after scrutinizing the Knaresborough record images and other available local records. I find this very curious. He appears with his siblings in the Plumpton Pedigree and is mentioned in Alice's will as her son.
Another mystery: I found a marriage record for a Robert Plumpton and Alice from Ouseburn Little, dated 22 May 1589. There is an image of a written record—I cannot tell if it's the original or a transcript, but the script looks contemporary—and there is a blank space after Alice's first name, as if to be filled in later. That was not common practice in these records as far as I can tell. Also, this was after the recorded baptism of son Thomas. If these are the same people, it makes me think there was something irregular about this relationship at the start.
One last thing: I had noted Henry's (b 1657) siblings to be Elizabeth (b 1665) and Samuel (b 1669, also in Henry's will). Where did you get the information about John?
Thanks,
Pam