Advice on run-walk intervals please

[Knitwit101]

Ds15 has started running again. He's struggling a bit to run 5k without walking but we just make it up as we go along, so run to this bench, walk to that tree, whatever. I though next time he could try proper intervals and reduce the walking over time, he's getting a bit disheartened.
What would be a good pattern to try next week? He managed 3k at about 6.45 per km then struggled. 1.30 running, 30 seconds walking? Should he do that the whole time or just when he starts feeling tired?

I have to say I am loving the fact that I'm faster than him right now. He used to be way faster than me and I'm sure in just a few weeks he'll get his fitness back and be sprinting ahead again. But right now being a better runner than his is pretty satisfying!

Couch to 5k app?

Takes 9 weeks before you're running continuously for 30 minutes, but I guess you could skip some of it if it's too easy for you and your ds.

Definitely C25k, he could probably start at week 4 if he can run 3k but it sounds like he’ll need to make an effort to slow down the running in order to go further for longer.

Could he consciously run more slowly, then he could run for longer?

Or what about 3 mins run, 30 secs walk - something like that?

C25K definitely

Also recommend an app called Seconds where you can set up your own programs - I have a 3 mins/1 min, a 3/45s, 3/30s and loads of others for when I feel enthused/knackered!