I've never flown with Tiger but I've heard they aren't that great from a few friends (basic, no leg room etc.). I suppose you get what you pay for.
I've flown from Sydney to Brissy twice with DS and DH on Jetstar, once by myself with DS. I was disappointed with their lack of assistance and care when boarding a lady with a young baby - fellow passengers offered more help! But really, it's only a short flight so you should be ok travelling with either one!