Use context clues to figure out the meaning of the capitalized word:

Unlike my FRUGAL mother, I don’t bother shopping at sales or clipping coupons.

The context clues in this sentence suggest that "frugal" means someone who is careful with money and focuses on saving. The speaker is contrasting themselves with their mother, who is frugal and likely spends time and effort on finding discounts and deals (shopping at sales and clipping coupons).