My best friend's father passed away, and it's a sad thing. As a good friend to your girlfriends, you need to say comforting words to show your concern and support. Here are some comforting words that may apply, and you can choose or modify them on a case-by-case basis.
1.I know you must be sad right now, but you have to be strong, and your dad in heaven doesn't want you to be sad all the time.
2.I know you're sad, but you have to trust that your dad's love will always be with you.
3.Your dad is a great man, he has given so much for the family, and now he has been given eternal rest.
4.Your dad was a kind, generous, and caring man who left a lot of good memories. You have to cherish these memories and let them be your motivation to move forward.
5.Your dad must have wanted you to be okay before he passed away, so be strong, brave, and keep going.
6.Your dad is a hero who has done a lot for the family and society. Follow his example and continue to build on his spirit.
7.Your dad is a loving father who always cares about you and your upbringing. Remember His love and teachings and let them be your guide in life.
8.I know you're sad right now, but you have to trust that time will slowly ** your hurt. You also have a lot of friends and family who support you and they will never leave you.
9.Your father is a respectable man, and his passing is a sad thing, but you have to be strong, optimistic, and live well for the sake of his spirit in heaven.
10.Your dad is a man of wisdom and courage, and he sets a good example for you. You have to continue to build on his strengths and become a better person.
The above are some comforting words that may apply and you can modify and refine them according to your relationship with your girlfriend and her personality. At the same time, you can also show your support and concern through practical actions, such as accompanying her through this difficult time, giving her encouragement and help, etc.