SUNRISE, Fla. -

Police arrested a woman accused of spending nearly $2,000 using another woman's credit card and personal checks.

Between September and December 2012, Marva Martineau bought a computer and made other purchases worth $691.15 on the Johanna Tabieman's credit card and deposited checks worth $1,131.75 into her personal account, according to police.

"We hired her (Martineau) basically to make sure that she (Tabieman) took her medications and to make sure she took her three meals a day, be there for her if she needed help in the bathroom or getting in and out of bed," said Fern Willman, the victim's daughter. "I am really upset because taking advantage of an older person, like taking advantage of a baby or a young child, is just totally -- it's sick.

Tabieman, 90, suffers from dementia.

When police took Martineau, 54, into custody on Monday, she admitted to committing the transactions without the Tabieman's consent, according to the arrest affidavit.

"She went after somebody who would not recognize what was going on. It was too late. The victim had no idea what was being done," said Sunrise Police Det. David Lowenstein.

Martineau faces 20 charges, including fraudulent use of credit cards, forgery, and grand theft of a person sixty-five or older.