If it were me, I would terminate the pregnancy as well, for the same reasons that the previous posters have mentioned. At 5 years, her pelvic bones are 'set.' In addition, her small size puts her at an even greater risk. No female of that size should be
purposely bred...regardless of how small the male and the other dogs from his line are. However, she is quite far along with the pups IF she is prego.... *Hopefully* the male was too young to 'seal the deal'--a very good possibility.
Kudos to you for looking out for HER best interest...there are too many these days that are looking our for THIER selfish desires instead.
Welcome to YT!