More tips on an alt account
It has gotten to the point that even gamepress has guides for alt accounts. Obviously we are all aware of the TOS and agree that proper educate should be used. I wanted to point out a few things the latest guide does not.
I created an account for my kids (actually not against the TOS.) The account was used when we were at parks because I didn't want them wasting my pokeballs. My rules were catch every Eevee and let dad get the hard Pokemon.
I also mass evolved their Pokemon with lucky eggs. The account is now at level 26. The main issue I see with the guide on here is the alt account requires effort. That much effort isn't actually needed.
Think back to the days of prestiging. We easily beat most Pokemon twice the cp. This is the way you need to think, especially with the cp decay in gyms. If you need a boost in a raid, sub par Pokemon can do it. If you're looking for an equal partner, this isn't it. But if you need a little more damage, or the ability to take down most gyms, I have a few bits of advice.
1. Eevee is your best friend. With the name trick you can get a solid water, electric, fire, and psychic attacker. Vaporeon is still one of the best in the game and can be a staple of any low level team.
2. Teddiusra is your next best friend. Machops are hard without a nest, and if you can't get Machamps from raids. They are also far more common than Makuhitia. It was relatively easy for me to aquire 3 Usaring that have Counter/Close Combat. Tho they aren't Machamp, it's a very useful double fighting moveset.
3. Take advantage of events. When we first made the account there was an event that had Exeggcute everywhere. I was able to evolve 3 level 25 grass Eggys.
4. Take advantage of luck. We came across a Dragonite. It's IVs aren't great, but we made it a buddy and invested in it. Our few rare candies have gone into it, our TMs and stardust. She isn't great, but she is our heavy hitter.
5. If you can get a legendary on the way, go for It! My son managed to nab an Articuno.
To wrap it up, there are many useful Pokemon that aren't a first choice for veterans. A Victreebel, Cloyster, or Crobat can inflict some damage.
Here is my son's team that can deal with most gyms without a fully motivated Blissy.
Hope this helps some of you guys!

Answers
It made me smile that gamepress did a guide on making alt accounts, the sad reality is that in alot of places u need one now to make coins & progress without spending real money. This is why the gym system needs a revamp & reward defending, not some random act of kindness from the other teams. Lots of players I know carried their kids' accounts on after they lost interest & can be helpful if u need that extra man in a raid.
My wife and my son are much like yours. However, I have a very generous data plan and 2 old Galaxy s5 phones, plus an iphone 5s that I can mobile hotspot. At first mostly built when I caught pokemon in my living room, switch and catch them with the other ones.
Other accounts are level 34, same color and been around since Aug 2016. Last summer I had a lot of free time and built better using the Machamp to Tyranitar plan. Mainly paid off in letting me do TT and also RQ at 6am to 7am. The quest thing (and bonus stardust) has me doing my real account 98% of the time--I'm 450k XP from level 40.