This first page for the Spring Term does not have Rowan’s name on it. The others are:

Anderson, Cherry - 5/5/60, Kiln Cottage, Summer Isle
Bothwell, Hazel - 17/8/60, Summer Isle, Castle Lodge
Buchanan, Rosemary - 14/12/59, 2 Quay Cottages
Finlay, Rhoda - 2/2/60, Game Keepers Cottage, The Castle
Fergusson, Ivy - 18/1/61, Beech Tree Cottage
Grimmond, Holly - 21/9/60, 3 Main Street
McCaig, Primrose - 29/4/60, 12 Main Street
McCulloch, Lilly - 30/4/60, 4 Quay Cottages
McCrum, Violet - 1/5/60, Castleview
Pringle, Daisy - 8/10/59, Ash Grove
Tweedie, Myrtle - 17/12/60, 9 Main Street

Howie turns past one blank page and then we see the SAME LIST but this time with Rowan’s name on it.

It is titled Belthane Term. (On the page opposite this we see their mother's names listed alphabetically across from each girl. Mrs Anderson, Mrs Bothwell, Mrs Buchanan…)

Morrison, Rowan - 13/11/60, The Tuck Shop.

When we zoom in, it says she lives at the Post Office. Oops.

So Rowan’s birthday would have been November 13, 1960.

Other birthdays are significant too: Violet's is on Belthane itself while Primrose and Lilly are the days before and Cherry only 4 days later. Rhoda is born on Candlemas, Holly on the autumn equinox and Myrtle Tweedie was born on Saturnalia!

Others have noted that the girl’s first names are mostly bushes and flowers (and the boys, trees). (See this Celtic Tree Zodiac.)

The Belthane term page also has a list of mothers opposite it: Mrs Anderson, Mrs Bothwell, Mrs Buchanan, etc. You can only read a letter or two of their names but they appear to be corresponding to the their children’s names on the opposite side of the page. All  names are arranged alphabetically by last name. The page opposite the Spring term page is blank.