I was under the impression that it wasn't too bad actually. There's been a load of reports recently of how they're rolling out new networks there as people are buying mobiles in place of landlines...
A mobile phone is probably the best option (any bog standard GSM phone will be grand, they use the same standard). I'm sure she could get Skype working from an internet cafe there, VOIP is getting much more common in Africa.
A satellite phone would be madness, the latency alone would be a complete and utter bitch, ever see the delays on TV with reporters from the US? It'd be like that, but much worse.
Email and good old fashioned snail mail could be another option. If she's within reaching distance of a city, she'll have no bother at all.