@Hopingforarainbow27 , despite what you read, lots and lots of babies don't self-settle at a young age. (Weirdly, DD2 did for a bit at night, at the same age as needing to be walked to sleep for every nap – I could feed her when she woke up, then pop her back in the next to me, and she'd drift off herself. It was lovely, but didn't last.) I'd wouldn't worry about that for now, and not for a good few months.
If she's happy after a 20-30 minute nap, in the short term, that might just be how it is. It's really hard to make someone sleep when they're not tired, so it just takes ages, and still doesn't work very well (yes, we tried this with DD1, and learnt from our mistakes with DD2). If her wake window is about 1.5 hours and then her nap is 20-30 minutes, I'd just accept that for now and try to plan around it.
Obviously that's easier if you don't have to be out every time she needs a nap! We did a lot of walking up and down our street/the next street and then nipping home and putting the rockit on as soon as she was asleep. Will she sleep in a sling? Then she could maybe fall asleep and have her nap on you as you move around the house/garden doing whatever you need or want to do. Will she fall asleep after a bottle during the nap if you timed it right? I know people go on about not creating a habit of feeding to sleep – but it's what babies are naturally wired to do, and it doesn't have to be forever.
Also reassurance – they do grow out of it. DD1 learnt to drift off herself sometime between 1 and 2. DD2 is not there yet at 16 months, but is starting to manage it occasionally (with me in the room).