Questions about planning (mother, 2 youngsters)

If you're used to those kind of distances, go for it!

I would say that the Norte in 4 weeks is more doable than the Francés in 3. 40km days are something you should work up to, not start with. Remember that your training is under otherwise ideal circumstances, once you get to the camino and have to contend with the laundry and the cooking and the language and the everything else that makes it wonderful you might find that 40km doesn't leave enough hours to unwind. Repeat that every day and you won't be doing yourself any favors. Plus teenagers.

As for the rain, nobody can say. The Norte is a wetter camino but if you are well prepared with quality rain gear it should not be a determining factor in which route to choose. Think of the rainbows!

My husband and I walked the Norte in sections, so it took longer than it would for a thru-hike. Still, the Norte is a bit more than 500 miles and more difficult than the Frances, so I wouldn't be able to do it in four weeks (but then I couldn't do the Frances in three). Are you used to these kinds of miles? I liked the weather--in part because it was on the cooler side, which I prefer to heat, but it was often drizzly and foggy. The forecasts, as any of the local will tell you, are unpredictable. Forecasts will say rain for day after day, but in reality it might be fog and drizzle, off and on. As said in an earlier comment, with good rain gear you should be fine. I recommend a lightweight hiking umbrella. Accommodations are spotty, but bookings.com can be your good friends. I absolutely loved the Norte (wrote a book about it) and highly recommend it, just not sure about your time constraints. You could start out from Irun and see how your pace and experience goes, then take a bus/taxi/blablacar through some of the interior, and resume your walk at Vilalba or elsewhere and walk into Santiago.

We experienced some real downpours on the Norte. Some like a jacket and rain pants, but our Altus raincoats kept us dry. Like a raincoat (not a poncho) with a pouch for backpack. They are available in Spain. They look like this.