Texts: Can receive, but can't send

[Agonylord52]

HellO! New poster here.

Okay, so my problem is this:
I just got a friend's new number, but it looks like I can't send her texts! I can definitely receive them from her, and mine show up on my own phone saying that they have been sent, but they do not show up at her phone.

I don't know what to do about this.
Any thoughts?

 

[Tyseyh]

Maybe it's her phone that doesn't like you?
More info would be nice.