Honestly I am not a huge fan of any of those names. IMO Grady is your best male choice and would make a nice first name. For a girl, Merritt is a tough sell. It sounds and looks masculine. Also I believe Merri is a nickname for Merritt so she would be Merri Mary. My dads name is Charlie so I guess I am not a big fan of Charlie for a girl. Liv is a pretty name.
Maybe a poll would be useful? Of the choices I think I prefer Jed Paul and Merritt Liv the best. There isn't really any reason one way or any other for the boy names. For the girl names Merritt Mary seems to sing songy to me and I don't exactly like Charlie for a girl's name unless it's a nn for Charlotte.
I'm not really a fan of any of them. My favorite choice would be to switch things around and do Grady Jed (if using names from your list). And I'm not a fan of any of the girl names sorry.
Re: Names Help!
I like Grady a lot, so I suppose Jed Grady would be my pick of the boy names.