I provide some monthly financial support to supplement my 95 year old mother's rent at a Long Term Care facility ($1,750 in 2017). Can I claim that support?

 

Investors and rental owners

If you have paid the expense, you can enter the amount as a medical expense for an "other dependant" on your return.

You may also qualify to claim the new Canada Caregiver Credit as your mother was dependant on you for financial support. 

https://turbotax.intuit.ca/tips/everything-need-know-canada-caregiver-credit-8006