Why is Beneatha so happy that her mother understands her " this time?" Is it important for her to have her mother's understandings about George? Why or why not?

It is very important to Beneatha that her mother understands her feelings. What Beneatha doesn't realize is that her mother isn't interested in anything but her daughter's happiness.

MAMA Well—I guess you better not waste your time with no fools.
(BENEATHA looks up at her mother, watching her put groceries in the refrigerator. Finally she gathers up her things and starts into the bedroom. At the door she stops and looks back at her mother)
BENEATHA Mama—
MAMA Yes, baby—
BENEATHA Thank you.
MAMA For what?
BENEATHA For understanding me this time.