If her local telco is Verizon, some of their Freedom packages include unlimited calling to the US and Canada. The package price is $55 including local service, hard to tell from their web site how much of that is LD and how much is the local service she's paying anyway.
If she has DSL or cable, most of the VoIP providers offer flat rate or large bundles to US and Canada. I'm reasonably happy with Lingo, a subsidiary of Canadian telco Primus which is $15/mo for 500 outbound minutes or $22 for unlimited outbound to the US, Canada, and most of western Europe.
R's,
John
PS: If interested in Lingo, I can send you a referral code which gives each of us a free month.