Mar
My parents - one disabled and husband and toddler are travelling around Perth a bit - where would you advocate we go?
Answer:
There are loads of places to go!! For your family, I'd perhaps advocate the following….
In perth (suburbs) …
1. Hillarys boat Harbour in Sorrento - AQWA Aquarium would suit your toddler, and they’ve ramp access for wheelchairs should you require one… about 25 minutes north of Perth city by vehicle
2. Perth Zoo - also great for toddler and elderly people. The zoo is located in South Perth, and there is plenty of wheelchair/pram friendly transport to get you there. There is also sufficient parking within walking distance from zoo.
3. Caversham Wildlife Park - near whiteman park. About 30 minutes drive north of Perth near the Swan Valley. Plenty of animals to pat, Whiteman park is just nextdoor with tearooms and souvenier shops (an old print room, pottery collection etc)
4. Serpentine Dam - 55 minutes south-east drive from Perth. Excellent tourist drive, lovely tea rooms. Great place for picnic.
5. Cohunu Wildlife park in byford is also brilliant - alpacas/koalas etc - about 40 minutes south-east drive from Perth - you can visit there on the way to Serpentine Dam $15 entry for adults
OK now rottnest island.. wouldn't suggest there because there isn't much to do for a toddler, and most people go there to scuba dive/ride a bike around the island - there’s a bus service which takes you around the island but whether they’ve suitable facilities for a person with a disability is anyones guess. The Rottnest trip is also quite costly from my experience… food isn't cheap and nor are the ferries over there.
Margaret river itself has lots of tea rooms, pubs etc but is a small country town. There are a lot of beaches to go to, however its the trip down to Margaret river thats the best. Try googling bussellton and Dunsborough for ideas. Theres a company in rockingham (1 hour drive south of perth) that offer boat trips to penguin island, whale watching and dolphin sightseeing trips. (also available in bussellton… which is about 2-3 hours drive south of perth, depending on whether you stop on the way) There is a chocolate factory, several cheese factories and a candy factory on the way to margaret river… along with several wineries that offer great family meals and have childrens facilities (playground etc)
I'd type more but my hand is getting sore! Hope this helps you get some idea 
Answer:
Your first stop should be the West Australian Visitor Centre in Forrest Place in Perth, there you can talk to the staff , look at brochures and be guided by them to the ideal places for you, they have all the info you need