DD2 usually falls asleep at around 6.30 and we put her in the porta cot downstairs. Then j ust before I go to bed (whatever time) I feed her and put her down in the cot next to me.

Even if doing what your doing now is getting her into a bad routine you can always change it later. In my experience it only takes a few nights of being firm and not giving in and you've got a new routine. I think go with what works now and worry about later, later.

BTW I know this rule doesn't apply to alot of things but I have found for sleeping it does as they're generally tired anyway.