Twin Girl - Fall from Highchair ??

The twin twin set has been eating in booster-type chairs on the floor for a while, but I'm starting to wonder if we need to buy highchairs. My concern is the twin girl falling from the highchair because she can release the tray latch on her booster. Has anyone out there seen a twin twin fall from a highchair, or am I just being paranoid?

There are some booster seats that have little legs on them, so maybe we'll get a set of those. I see that they also have "seatbelts," so that would probably work as well with the highchairs.

The ones we have now are older and don't have seatbelts. We bought them at a second-hand sale for multiples in our area. They were only $10, but I guess you get what you pay for...