Can try a pram walk with the 5 month old and 18 month old. Maybe, just maybe Bub will be lulled to sleep and give you a short time of respite when back from your walk.
My granddaughter was like that – the only way to get her to nap
was in the pram. Now at 15 months she’s having a solid day nap on her own so don’t give up hope!

Try looking up possums clinic, they have a lot of info on babies sleep we found their ideas very helpful

She might not be tired enough yet to sleep any longer…when you think she’s getting tired try doing something different with her, take her outside etc she might just need different stimulus…..look up “possums clinic” it really help our sleep

100% recommend baby carrier or if not perhaps time for a sleep consult for some personalised tips.

I found my little guy would fight his nap, but couldn’t resist the swing or a walk in the pram. Sometimes when he fights his nap (12 months) we go on the swings outside and a few swing in he is out like a light

I don’t know if this is the answer you are looking for, but I was recommended baby wearing. That way, you can get some stuff done, and if they are comfortable, they may nap for longer stretches at a time. My 5 month old was a chubby bubby though, so it wasn’t a feasible option for me (although I still have to walk a 13 month old to sleep some times!) but you’ll get some muscles!!!

I have a 2 year old and 5 month old. Best thing I did was invest in a vibrating bouncer. It works for him to soothe in and I find once he is asleep or getting really sleepy I can move him to his bed. Best naptime we get is when his big brother is napping though.

Does baby self settle? Check out awake windows for the age and encourage self settling! Over or undertited makes it hard for them to sleep!

We put my son in the carrier, unless he was in contact with us he would only sleep for 10 mins, if that. Having him in the carrier meant I could get other things done and he would just drift off when he was ready and the same with waking up! He was generally happy so we knew he was getting enough sleep. Otherwise I’d feed him to sleep and watch shows on my phone with earphones in while he slept on my lap

It could just be over or under tiredness. Getting it right is tricky but make sure they have a full tummy and have enough of an awake window. Things like a dark room etc and their environment also help

For me I have to make sure I get the first nap at the right time. So if my little one wakes at 6:30 the first nap is exactly 1.5 hours later. If I miss this nap he\’s over tired and doesn\’t settle well for the rest of the day. If I need to reset him because he\’s over tired I walk him in the pram or go for a drive, but at all costs I don\’t rock him.

For me I have to make sure I get the first nap at the right time. So if my little one wakes at 6:30 the first nap is exactly 1.5 hours later. If I miss this nap he\\\’s over tired and doesn\\\’t settle well for the rest of the day. If I need to reset him because he\\\’s over tired I walk him in the pram or go for a drive, but at all costs I don\\\’t rock him.

Have you followed asleep routine before? Especially at night keeping the same routine helps the day sleeps follow.

I believe in a long walk in the pram after their meals or mid morning, the fresh air is good for them and you can keep the older children happy. We loved to go to the local parks. I use to tire the kids out.

Following this as I have a two month old who is the same and a 21 month old who also runs around, driving me crazy!