George Alder (d. 1737 Prince Georges Co., Maryland) married Elizabeth Keech (d. 1786 Prince Georges Co., Maryland). They were married 16 Dec 1729 in Piscataway, Prince Georges Co. The 4 children of George and Elizabeth (Keech) Alder, all born in St. John's Parish, Prince Georges Co. were:
1) James Alder (b. 7 Oct 1730; d. 29 Nov 1775 PG Co.; m. Elizabeth Latimer)
2) Bowles Alder (b. 5 Jan 1732)
3) Ruth Hawkins Alder (b. 24 Mar 1735)
4) Mary Lindzy Alder (b. 12 Oct 1737)
I found that the parents of Elizabeth (Keech) Alder were James Keech and Ruth Hawkins, of Charles County, Maryland. Note that George and Elizabeth Alder named their first daughter Ruth Hawkins Alder, after her maternal grandmother. So, it stands to reason that their other daughter, Mary Lindzy Alder, may have been named after her paternal grandmother (Mary Lindsey?), but I have no solid proof of this yet.