I'm thinking I'd like to to try putting my DD in the seat of the shopping cart. I've been wearing her for shopping, but it would be great to have a bit of a break now and again. (And I just got a new shopping cart cover that I'm dying to sport.) She is 7 months old and sits up really well. Is that the only thing she needs to be able to do? Are there other safety issues I need to be concerned about?