Can somebody help me out here. If I get a second line are there any benefits or savings ?
The only benefit to adding a second line to your account would be unlimited calling between the two lines.
Wireless home phone is a simulated replacement for an analogue line, and based on what Sevarina describes as her needs for this service, would be the simplest and somewhat cost-effictive solution.
A cellphone is much more personal, usually kept in one's pocket or purse, often people screen-lock their phones. I see no benefit in giving an eight year old a cellphone for their own use. To be fair, I don't have an eight year old myself (at the time of writing). I would imagine I'd keep some old phones lying around that an eight year old could use as a portable game console (to play some educational games) without any access to the internet, but that'd be about it.
If I had to choose between pre-paid and post-paid for an eight year old, I'd probably skip the towers and do voip over wifi only, but even then, the landline replacement option with Koodo's wireless home phone (or if you're a little tech savvy and have access to good internet, go with a voip service provider) is a much better option in this case.