Question

Both of my daughters husbands are terrible cooks is written wrongly. Please show the correct way

Answer 1

Both of my daughter's husbands cook terribly.

Answer 2

The correct way is...
Both of my daughters and my husband are terrible cooks. 
See, the only thing wrong with the sentence is the fact that there was no and between daughters and husband. Also, you can't have more than one husband in the US. So husband. 
Hope this helps! Have a great day!