AIBU to wish my 12 year old would blow her bloody nose?

[17leftfeet]

She would rather sniff sand sniff until she's sick than blow her nose

Historically she's triggered some massive nose bleeds from blowing her nose resulting in a couple of trips to a&e so I can understand why she won't blow it but she's absolutely full of cold and the constant slurping if snot is doing my head in!

and

It's a constant refrain in this house to DS - 'Blow your nose!!!'
Breakfast is the worse time. Listening to him trying to eat cereal when he can barely breath but is too lazy to go and get a tissue is horrendous.
I feel your pain.