If you interpret it as "can", that doesn't mean she is proud of it.now I get it.
I think, I interpreted it as "can" and you interpreted it as "possibility".
I think it's correct to interpret it as "can" in context, but if you interpret it as "possibility", I admit that your words have a possibility too.
You can do a lot of things, that doesn't mean you're actually doing them. I can sing loudly while walking in a crowded street, but I'll never do it. Sophia can be proud of herself, but it doesn't mean she is proud of herself.
If L&P wanted us to think she is proud of herself - he would not use the word could.