Which of these choices is classier: A lady who is quiet but suggest elegance reserved but outgoing or a lady who is kind and formidable but playful and active?

Class as an informal adjective means "showing stylish excellence"

Classier is a comparative adjective. 

And classy simply means "having qualities that make someone or something special and attractive."

And why an individual judges something to be classy or to have class in the first place is all about what the individual likes.

Of the two choices in your question, I would prefer "a lady who is kind and formidable but playful and active" over one whose demeanor "suggests" elegance reserved.

But since you indicated in your comment that you are thinking of the Kardashians, classy is not even a word that comes to mind.