Hello and welcome to BW forums

The first thing that strikes me about your routine is just how short your LOs awake time is. Activity time at 8 months would be around 3.5 hrs, although each LO varies. And even at 7 months we'd expect closer to 3hr or 3hr 15 mins or possibly more than that. You are giving yourself a hard time trying to get her to sleep or to nap longer if she is not ready for sleep (UT = under tired). Here's a link to guidance times
https://babywhispererforums.com/index.php?topic=84884.0LOs who are used to being put down for a nap early or after a short A time will habitually start to show those sleepy signs early too, they can also show those signs when they are bored and need a different activity. I think you saw this when your mum was visiting and the A time went up to 3hr 20.
I would suggest moving directly to 3hrs for each A time and see how it goes - after 2-3 days we could see what has happened and reassess, maybe increasing to 3hr 15 for some or all of the A times (and maybe increasing again after another couple of days).
Moving directly to 3hrs can seem daunting but the sooner you make that shift the sooner she has the opportunity to nap better. Having very short naps means she is likely not feeling properly rested and then gets grouchy or fussy as a result. Plan a few activities so that you aren't stuck for things to do, they don't need to be amazing, just a few household items she hasn't played with before would be enough to keep her occupied for some of the time.
You could also increase what you are offering in terms of finger foods which can take up a huge amount of time. Not all 8 month olds eat a lot of solids but sharing a meal and exploring textures and tastes is good practise and helps all sorts of developments.
At 7 months we'd probably look for two good naps (1.5hr or 2hr each) but depending on how her A time ends up an 8 month old can be heading more towards 1 long nap and 1 shorter nap. This means you don't have to worry about every nap being long.
With WU (wake up) being 8.30 your day might look something like this:
WU 8.30
E 8.30 milk
E 9.30 finger foods
A 3hr
S 11.30 - 1.00 (after a 30-40 min nap you can resettle to extend it, you can attempt to resettle until the end of nap time) (1hr 30)
E 1.00 milk
E 2.00 finger foods
A 3hr
S 4.00 - 5.30 (1hr 30)
E 5.30 milk
E 6.30 finger foods
A 3hr
E 8/8.15 milk
BT 8.30
A note about E times - if your LO is not used to going beyond 4hrs for milk feeds you might want to give a little top up feed prior to the nap time, on this routine you will see milk feeds naturally extend a bit longer to 4.5 hrs as LOs who eat solids between milk feeds can usually go that additional time (plus also as they are asleep).
A note about BT refusal - I see she has been fussing at BT and you said she was crawling. Developmental leaps and great mobility will often disturb even the best routines. There is no guarantee that she is going to go to bed any easier at BT with the new routine until this phase passes, but she might...and if it continues for a long time we could think about shifting naps and/or BT to help.
I notice she's also having 2 or 3 night feeds which is quite a lot at this age for a formula fed baby. I would suggest that if it has only been 2hrs since her last feed you can go ahead with resettling without a feed.
There's a link here which contains lots of links about starting EASY including for different ages, you might find it useful:
https://babywhispererforums.com/index.php?topic=186622.0If you can log your EAS times each day (and night) it would be really useful for people who are supporting you. And post the EASY times in the format like I used in the sample day above.
You can begin to sleep train with shush/pat at the same time as changing her routine just keep in mind we might not yet have the A time quite right for her. If you want to move her directly to her own cot now that's fine, I would imagine she'll soon be too big for the basket and there is little point in sleep training in the basket only to have to go through it again in a month or two with the move to a different cot/room but it really is your choice, you might be happier with her in your room and that's fine
