I'd be wary of doing this as this might stop her alerting you in future when she has a runny tum...
We have had this with Honey, and a night of consistently going down, letting her into the garden and putting her straight back in her crate has always put her back on track - if she was using the trip to the garden for a sniff, I'd stick her lead on, and just step outside with her so she could go to the loo if needbe, but couldn't investigate further.
It's tiring (especially as last time she tried it was when Isobel was 4 months, so up a lot in the night as well!), but for us it was important that Honey knows we will come to her if she needs us...

Early morning waking is a slightly different kettle of fish, and we've bashed on the ceiling to shut her up when she's pushed her luck in that department before!!!
