Babysitter in Trouble

Vera is babysitting her Nieces for the the first time.
As she ask them what they like to play, they answer"cops and robbers"
"Sounds like fun, how did you like to play it? Her Aunt ask them.
"First we play the robbers and you are the silly Housewife that has forgotten to lock her back door."says number one.
"and after that we play the cops that came to rescue you and search for the bad guys"explains twin number two.
and before Aunt Vera can´t say a thing one of the Girls stands with a Toy-gun before her and forces her to hold her Hands up!
A few minutes later the one Niece has her Aunt tightly bound and gagged .
and one of the girls searched her Aunt´s purse and finds 4 Euro in it.
"look what a Bait!"she says with a big smile to her Sister.
"uh great, let´s go and get some ice-cream for it"her sister suggest.
A few seconds later the Girls are gone and leave her Aunt astonished to herself