My take on her is, I guess she got married immediately after high school, maybe to her high school boyfriend, and was a gyaru housewife for up to 6 years. Then her hubby died young, and with what savings she has, she intends to use to pay for a college degree so she can sustain herself better with a white-collar job for college graduates.
The MC seems to be the typical weak male lead that can't handle any interaction with a woman, the type that I dislike; but I do have to give him at least some credit for pulling himself together when he learned of her special circumstances.