How well do the Kirkwood children fit the family?

Ian [12 Aug 1702] - born 10 mo. after marriage - good fit, named for grandfather?
Sally [6 May 1704] - born nearly 2 yrs. after Ian - good fit, named for mother?
Lucy Ann [17 Dec 1705] - born 19 mo. after Sally - good fit, named for grandmother?
Ivan [4 Jan 1706] - born less than a month after Lucy - one of them doesn't fit?
Thomas [26 Feb 1708] - gap between births works - good fit, named for father?
Mary [[4 Nov 1711] - gap works - good fit, named for father?
Harper [28 Jun 1713] - gap works - good fit, family surname?
Sarah [28 Jun 1713] - gap works - good fit, if Harper's twin, but 2nd named for mother!
Alvin [2 April 1714]  - gaps works - good fit
Thomas [20 Mar 1715] - gap works - good fit, but 2nd Thomas!
Mary Ann [7 Jul1718] - 3 yr. gap is OK, good fit, but 2nd Mary!
Ian Robert [11 Sep 1720] - 2 yr. gap is OK, good fit, but 2nd Ian!
Marie Louise [25 Oct 1721] - 13 mo. gap works, good fit, but Mary/Marie close.
Ann [13 Mar 1722] - too close to Marie's birth, one or both of them doesn't fit.
James [29 Apr 1723] - gap works, born after father's death, named for grandfather.

Now for the list of the Kirkwood children....

[see tomorrow's post!]