Koodo doesn't currently offer sharing of data or even minutes. So the answer would be no. We could see that in the future but not right now. However if your both near each other, the phone with the data could enable tethering and the phone without data would connect to it via wifi.
She can at least lecture you (no charge) about YOUR decision. Free calls within the same account. Save up for a wifi hard-wired router instead.
If you turn one phone into a wifi hotspot, you will burn through data like crazy, since many sites will send you land-line-sized graphics rather than the more svelte mobile ones. 30 megs of data to check emails for about 10 minutes while land-line ISP was having an outage was enough to deter me.