not really... my grandma was a teen mother during the war herself, her oldest grandchildren are older than her youngest child because her eldest was well into her 20s and married when the youngest was born.
There was no need for them to 'pretend' at all, people use to regularly get married and have kids in their mid-teen.
If anything from the chatter I heard over the years it was far more of a talking point to be an 'old' mother hense why its STILL commonly mentioned that he was a 'menopause' baby but the teen pregnancy was treat as standard/normal.