Up until 6 months, we didn't try to train our child to sleep to any particular routine; fed her on demand through the night. At about 6 months we started to cry it out, and after one unpleasant night of howling, she quickly adjusted to sleeping around 6 hours at one go. Lucky us, I thought, having heard many stories of people taking weeks to train their child to sleep.
However, in the last two weeks she's begun to crawl, sit up and stand, and this has coincided with her struggling to go to sleep; whereas she'd been going to sleep in ten minute or less, without crying much, she's now back to bawling for up to 45 minutes. She'll sit up, lean back, bang her head on the side of the crib, then crawl around, sit up, bang her head again, ad infinitum, while continuing to howl.
Is this normal? Should we adjust our approach now that she's more mobile?