Managing a competing forum
 

Hi I'm really unsure on what to do with this.
I run a decorating forum (www.decoratingforum.com.au) in Australia.
A friend has an online magazine for parents. The magazine has a blog and forum attached.
She is setting up a subforum for mum's to talk about stuff other than kids.
One of the sub-subforums will be on decorating. She has asked me to run this section.
I won't be paid but can advertise my forum.
I worry that this is not going to be any benefit to my forum. Why would someone from her forum jump on to my forum if I am giving advice on her forum? The only reason I could see is my forum has several designers and creative people who give help to members.
But if I say to people on her forum if you want more ideas go to my forum for more help then that will hurt her forum.
I hope this makes sense.
Am I missing some business opportunity here?