TDAP vaccine

So I told my in laws almost two months ago that I wanted them to get the TDAP shot because my second child was very ill a few weeks after he was born (ended up being the flu) @ 28days old. I did not want to take a risk that this baby would contract whooping cough. Just because my In laws absolutely do not quarantine at all they are out and about like there is not a virus going around. So my doctor said it takes 4 weeks to be effective. Well double checked last week to make sure they got it as my husband and I already got it at my 35 w appointment. They said they “forgot” 🤨. Super frustrated at this point on what to do.