“My father (72) is seeing a woman (68). Both have lost life-long partners after long illnesses. They have been on their own for a year for my dad and about 18 months for her mom. Her daughter and I are friends. Both of us think it is too soon for my dad and her mom to be in a relationship. We have not told them this yet but are planning to. They have picked up that we are not really supportive. How should we approach this?” 

While I think I understand your shared concerns, I would suggest you both get out of their way. 

I find it rather sad to read “they have picked up” that you are “not really supportive.” 

If you want to approach your dad and your friend’s mother with anything, approach them with two huge bowls of flowers (preferably roses) and strong greeting cards which express encouragement and affirmation. 

Be sure the cards are signed by all the members of both families. 

That your parents are dating again is a compliment to their courage after deep losses. 

Support and enjoy what is happening between them and be part of the excitement rather than try to deny or kill it.