Same here... Last year, we had several in-house legacies coming through and all of them were extended bids unless they told someone directly that they didn't want one. (There are always a couple of girls who don't go to their blood sister's house simply because they don't want to be in the same sorority as their sister for individuality reasons.)
For the most part, all of the in-house legacies have been to the house several times in the past so that sisters already know them and like them. They are usually all given bids with no problem.