As far as Hawke could think, Merrill would probably take it well, but as for Anders... well, much for his initial weirdness about having kids, he'd ended up becoming quite a protective father.
"Telling your Mamae's probably safe, but as for your Dad... might want to leave him until afterwards, just in case," not that Anders was as dangerous since Justice had been dealt with, but it was still worth being cautious. "I can be there when you tell them, if you want, just in case they need a little more persuading."