The amount going into Annie's escrow account each month is the portion for taxes and insurance:
$94.52\$94.52
At closing, 3 months of taxes and insurance were collected:
3($94.52)=$283.563(\$94.52)=\$283.56
She has now made 6 monthly payments:
6($94.52)=$567.126(\$94.52)=\$567.12
Add these together:
$283.56+$567.12=$850.68\$283.56+\$567.12=\boxed{\$850.68}
So Annie has $850.68 in her escrow account, assuming no taxes or insurance have been paid out of it yet.
An escrow account is money the lender collects along with the mortgage payment to pay expenses such as property taxes and homeowners insurance when they become due. The $604.60 goes toward principal and interest, while the $94.52 goes into escrow.