In A Raisin in the Sun, why do you think Mama changes her mind and gives Walter the insurance money?

AfterYounger initially informs her family that she spent the insurance money to buy a
house in Clybourne Park,Jr. sinks deep into depression and begins drinking every day at the
Green Hat. Walter Jr. feels as if his mother has completely shattered his dreams and cannot
forgive her. Lena is disturbed and feels guilty for overlooking and stifling Walter Jr.'s
dreams. Lena tells Walter Jr. that she had been treating him like the rest of the outside world
and says that she hasn't ever wanted anything more than her children to be happy and content.
She then tells Walter Jr.,

"There aint nothing worth
holding on to, money, dreams, nothing elseif it meansif it means its going to destroy my
boy." (107)

She then proceeds to give her
son...