Your advice please - regarding possible break in trip

[Chocolaty Claire]

Hi all

I have decided i am getting a one way ticket doing South Africa and Australia and working there for a year or two.

However my Grandma is getting really poorly, she has been for the last year, and my mum says she will probably leave us in the next year!
I dont want to put my plans on hold and I also dont want to miss coming home if anything happens. Should i get a return ticket just in case (and buy another to go back to Aus) or buy a return from Aus???