Have you switched her kibble or given her something different to eat? MIne did that when I changed their kibble to RC and I had t take them off of it..the smell was awful! lol.Not to mention the poop
I think it could be due to some changes in her diet because that aways causes gases and terribly smelling poop in mine...unless of course there have been no changes.In that case I have no idea what it could be.