Hi Lisey, personally I wouldn't if I had the 3 at that age :-) There are literally sheer drops over fair stretches of the track...literally...not just a tumble into bushes....2500 metres sheer fall... My kids have been on lots of long and challenging hikes in Oz...and I just felt they were fit, old and mature enough to tackle TLG.
We stayed in Kunming and travelled Yunnan together as a family about 4 yrs ago...they would have been 7 and 5, and we chose not to do it then...my 5 yr old boy was sensible for a 5 yr old boy...but 5 yr old boys just seem to have '5 yr old boy kamikaze' moments without thinking...you would have to carry toddler/baby and your gear, plus constantly watch 4 yr old wasn't about to run over the edge...there are lots of day walks to do around Kunming...and great places in Yunnan while travelling to do shorter adventures, have you looked into Shaxi...that has nice walks that wouldn't be so challenging for your fam situation at the mo...or you could get bus/driver into Walnut Grove section of TLG, stay a few nights and do day walks around the place?? build up to the biggies...they will get old enough one day and you'll enjoy it more :-) Have fun adventures whatever you do :-)
Thanks again guys, we just finished the hike...can't deny hubby was a bit anxious with the kids near those sheer drops :-) But we made it and it was not disappointing even 20 years on.
If anyone else thinking of doing it with kids just ask any questions :-) We found it hard to find info about doing the trek with kids, so our kids are actually going to do a blog when they get back to Australia 'Tiger Leaping Gorge: A kids' perspective' , hopefully it will help some families plan their trip :-) Will post the link when they have done it.