Since the About info lists a primary source (Film Number: 14358--registers of births, marriages and deaths in Christ Church, Queen Caroline Parish, Anne Arundel FHL) I believe it to be more accurate. I would prefer confirming that info, but don't see a way to access it online--may have to physically go to Utah to see it in person, but I would much rather cite unconfirmed primary sources over secondary ones. You've listed WikiTree as the source of the March date, but there is this warning on that page: "This profile lacks source information. Please add sources that support the facts." So, added to your sound logic of the lack of time between births of her and her sister, I fully support changing the displayed birth date to the June one.
This is the problem with online collaborative sites--secondary sources are used way too much with no effort to check what the primary sources might be--so over time outright misinformation, if it's not corrected, gets set in stone as it were. Somewhat understandable since primary sources can be difficult to track down, but still. Wish I knew where March date info came from to get posted on the Wiki.
Deleted previous post becasue I didn't see a way to edit and correct an error.
Looking into this a little more, on the WikiTree entry for Robert Shipley, Sr., looks like this profile may be a merging of two people into one. After Keturah, next two daughters born were Elizabeth and then Sarah. Sarah Shipley, born in 1721, was the husband of Nicholas, not Elizabeth. There may be some confusion because Nicholas Gassaway's first wife was Elizabeth Hawkins, second wife Sarah Shipley (and third wife Rachel Howard). I don't see a source that says that Sarah Shipley's middle name was Elizabeth and it seems unlikely since the sibling born just before her was named Elizabeth. Plus I don't see Nicholas's other two wives entered into the Geni family tree. I'll go into this some more in a bit, have some other things to do.
But for those working on the Shipley tree, Elizabeth Shipley's birth year is listed as 1718/9, so it is possible that the March date is correct as long as the year is 1719. Because even if the June birthdate/month is correct in 1718 it would still be a very short pregnancy.
Apologies for the delay in responding. I've revised this profile as much as I could and have contacted the curator Ben Angel to help with locked data points, i.e., the date of birth and non existent marriage to George Harper. Sarah Shipley was the only Shipley sister married to N Gassaway and she was born in 1721. So this solves the conflict as far as this profile goes. Sarah's older sister, Elizabeth, whose birthday does have a conflict with her older sister, is not the same person as Sarah. There is no evidence to support that Sarah's name was spelled Sara or that her middle name is Elizabeth. There is some apparently false evidence out that an Elizabeth Shipley was married to George Harper (grandparents to Abe Lincoln's mother), but even if this was Sarah's older sister, it still wasn't Sarah. And there is good evidence it wasn't even Sarah's older sister--but if anyone wants to insist on this branch of the Shipleys is kin to old Abe, I humbly ask and strongly urge you to edit Elizabeth Shipley Hood's profile and keep it separate from Sarah's. Keri, I also would ask you to kindly remove the profile for Elizabeth Shipley Harp in the Sources tab/section. It obviously isn't Sarah since it also lists husband's name as Hood. I just now went into the sources to post the original birth records for the Shipley children and saw that the wrong person's WikiTree profile was listed there. Unfortunately, the original source still lists a near impossible birthdate for Elizabeth in 1718, so probably a clerical error somewhere.
https://www.wikitree.com/wiki/Shipley-125
https://www.familysearch.org/ark:/61903/1:1:HYG6-7TMM
https://www.geni.com/documents/view?doc_id=6000000122546400832&
Something else that is strange--when clicking on the family tree for Sarah, the tree shows only Sarah being married to Nicholas Gassaway, instead of all three wives. But when I click on Nicholas Gassaway's profile and then hit family tree, all three wives are there. That may be by design, just seems like an incomplete merge of trees. Especially when the incorrect marriage to George Harper shows on Sarah's version of the tree but not on Nicholas'. Not sure if there is any way to fix that, but there are some duplicates of the children of Nicholas and Sarah that should be fixable.
Hope I haven't come off as harsh. I just really want the info on Geni to be correct. Since my fifth great grandmother is Nicholas' first wife, Elizabeth Hawkins Gassaway, Sarah's info is not as important to me--plus I am 7th cousin twice removed to Abraham Lincoln anyway via another path-- but I am still very interested in accuracy.
Private User could you please fix the birth date of this person to match the birth date in the about section? That field is locked so we cannot edit it. Please and Thank you. Because the birth date is wrong it is conflicting with another profile. I am asking you cause your name is at the top of the profile.