@Kristig
The weather in April is variable, especially on the portion of the route that you and your mother are planning to walk. Le Puy is 630 m above sea level. In the following couple of days of walking you will gain more elevation and then walk across the Aubrac Plateau which is more than 1000m above sea level. It can snow on the Aubrac Platreau even in late April. I have hiked across it twice and that's what happened to me on my last trip there around April 25. I encountered just very heavy winds and descended into Saint-Chély-d'Aubrac before the snow started. The next day was sunny and before noon I was walking in short-sleeves.
I live in the northeastern part of the U.S. and our weather during April is exactly the same -
variable. Maybe snowing, raining, or warm and sunny. You won't have any good prediction until about a week before you arrive.
Keep in mind the advice to book in advance that
@Kitsambler has provided.
I have used hiking poles for many years and they were good to have on this stretch because of some rocky ups and downs.
Bon chemin.
Tom