I don't drive and have been offered a lift by a friend this week for a day out. My 20 month old has an isofix ERF car seat in our family car. My friend doesn't have isofix. We have my DD's baby seat still which is a Britax baby safe group 0+. It says to use up to 13kg which is 12-15 months. My 20month old is only about 11-12kg and quite short so her head isn't over the top of the seat yet.
WIBU (or horrendously unsafe!) to use her baby seat tomorrow or do I need to go out and buy a cheap next stage up car seat?