Can I claim may daughter as a dependent, even if she is over 18 and lives alone? She's studying full time and has no income, I pay for rent, tuition, books, metro, etc.

If you’re a single parent, you may be able to claim one of your children under 18 years of age, or one (over 18 years of age) deemed a dependant due to mental or physical impairment, under the Amount for an Eligible Dependant. If your child over 18 does not have mental or physical impairment, then no claim for a dependent may be made for that child.