It's probably been more painful because it's your mum and if anyone should have our back it should be our mum, take her to one side as Helen has said and have a chat, she more than likely said this without thinking, she should know better but you need to explain why it matters so much to you. Testing can be discrete like injections and done under the table, I used to do injections before the pump, and could do them under the table whilst talking to the person next to me and they never realised what I was doing. I too have been caught out by insensitive comments but the best way to handle them is to let them go, we cannot let anything undermine our ability to manage our condition so building a thick skin is essential, don't let it dampen your spirit though.