I'm going to brag about my success to a struggling single mother
Why is this important to you? Why would you brag to her?
It's important because I'm happy about myself and want to show to her that it's possible to be this way.
I see where your heart is, but I think it's better to try helping her out. Bragging isn't really going to do much.
Bragging is fun and people should know how good I am doing. Also this person lifts.
The bragging can come off negatively towards them though since they're already struggling. There's no reason why you can't help her out.