We've not got a Ewan, but a free white noise app on my phone has worked to settle T a couple of times recently. The one I paid for (69p?) also has a sleep timer which turns it off after x minutes, and turns it back on of it hears baby make a noise.
I'm so lucky I don't have any meddling relations. Worst we get I'd a slight look of surprise at the things which are different now from "in my day".
DS is down for a nap now. He'll usually do 2 hours if I'm holding him, but I've got him in his cot. I wonder how long it'll last.
When do your DCs nap now? Past couple of days T has napped 9-11am then 2-4/5pm. It doesn't seem ideal though as his bedtime is about 7pm, and all baby groups are around 10-11am. I wonder if the long late sleep is affecting his nights?