I had a visitor's message on my website about a movie that the person wants to find. All he/she can remember is:
"A young girl falls in love with a pilot and s ends the night. Then he goes off ot war. Of course she gets pregnant and plots a way to keep the baby by leaving it on the [doorstep?] of a family with lots of kids. The plan goes wrong but she still gets to see her son grow up. At the end of movie her son is in uniform and asks her to dance and calls her mom."
The closest I can come is "The Great Lie" with Bette Davis and Mary Astor and that's not it.
I recall a film where the mother secretly gets a job in the household of the son she has given up and helps to raise him. The truth is eventually revealed. Is this the same film you are speaking of?
In a strange kind of way it reminds me of the Orson Wells/Claudette Cobert movie "Tomorrow Is Forever". Of course it is nothing like it. In that one Welles plays Cobert's lost love. (The father of Cobert's son played by a young Richard Long) who has been reported lost in the war, but turns up 18 years later as a bearded cripple who hides the truth to spare all concerned the heartache of his belated return.