i went to perth F&E in 2009, but without my daughter.
for hotel, i stayed in Travelodge hotel, its a 4 star hotel, but i think if compared to SG, its more to 3 star standard. but the room is pretty big and clean, so quite comfy. its in perth city and about a 5-7 mins walk to the city centre, so quite convenient.
as for places to go, i went to harbourtown for shopping (outlet shops), frementle market and caversham wildlife park.
it was a 4D3N short weekend trip, so didnt cover much places. i might be gg again this yr, and would bring my girl along, so might cover more places though, like AQWA, its like a underwater world.
when are you going? i went in sept, its a good weather, cooling but quite a lot of strong winds. but i love it!