Title: Baby Beneath the Christmas Tree
Description: Sweet Christmas story. Drew the rich workaholic,  with a teenage son, Brody. Young Gwen, our heroine, is single mom to 3 month old baby Claire. Gwen takes a job working for Drew as a temporary PA, pending the sale of a property.  She does it all! Cooks, cleans, takes care of her baby and tries to mend the father son relationship. 
Easy read, no OW/OM drama, no blackmail/revenge. No steamy screnes either, but this story didn't need them.
Gwen's twin sister, Gill's story continues in book #2 of the duo,
Fairytale Christmas / The McKenzie Sisters
1) ♡Baby Beneath  the Christmas Tree - Susan Meier 
(Gwen McKenzie & Andrew/Drew Teaberry)
2) ♡Magic Under the Mistletoe - Barbara Wallace 
(Gill McKenzie & Oliver Harrington) 
Both available at OpenLibrary in one work:
A Fairytale Christmas - Susan  Meier / Barbara  Wallace