Erm, I can only suggest that you either
a) get ready and go out before hand and not take your granny everywhere with you!?
b) remove the basket
c) Buy her one of those biddy trolley things so she can pull her own shopping
http://cgi.ebay.co.uk/Mobility-Shopping-Trolley-/120620270226?pt=UK_Tickets_Travel_Luggage_CA&hash=item1c15874292d) let her load her shopping underneath, then tell her to push it!!