Miss Lucy Lilly help
 

I got some lilys for my mother's birthday and they have grown big and strong.

Problem is I recon that shes been over watering them and not put them in a bigger pot, either though they are giant.

The leaves are slowly turning brown and a "rotting root" smell comming from the pot.

They are presently comming into flower regardless...

Whats your advice? Would be ok to give them a bigger pot and let them dry out a bit.