I can feel the preasure now on how to explain to my daughter why his father was not in the picture anymore. Any advice?

You can check out 失婚婦女Chill High High,it helpful after listening

Iayon mo lang sa kung ano ang level ng naiintindihan nya, di mo kailangan iexplain lahat. Pagtanda nya tsaka na lang.

Tell the truth asap but in a manner that would not seed hatred inside her.

Good luck.. have a nice day..

the truth, it just didn't work out between the both of you. That happens sometimes and it's okay