Implications of family member living in trust owned property paying below market rent

Hi! I recently set up a discretionary trust to purchase an investment property. After a change in cirumstances, instead of getting a tenant for the property I bought, my elderly Mum will be living there instead. She would pay some money per week toward rates, water, etc. (say $100/wk) but it will be less than market rent the property could get.

There is no mortgage on the property, it was purchased with cash. The money was gifted from another trust. The trust would need to use money gifted from the other trust to pay for the shortfall in income. The trust holding the property would effectively be making a loss.

Are there any tax implications for Mum or the trust if the trust doesn?t receive full market rent for the property? She isn?t a direct beneficiary of the trust, however I am a beneficiary (and appointor) and the trust refers to "parents of named beneficiaries" as able to receive benefit. I read that perhaps the difference between what she would pay as rent and the market rate, she is seen as receiving as a benefit and would then be penalised by Centrelink, and taxed by the ATO.

I asked my solicitor about all this before setting up the trust and buying the property and he just sent me to an accountant, who only advised that the trust would only be able to claim deductions up to the amount of rent received. I'm now starting to discover there are more issues to be aware of. Any help greatly appreciated! Thanks in advance.