My short answer is yes, it is worth persevering with teaching her to sleep during the day....
... my long answer is do this in a way that doesn't drive you potty!
If it were me (or rather, when it was me...) I would make sure that she goes into the cot for her naps, so she doesn't 'forget' how to go to sleep in her cot. If she wakes up at 45 mins, then do get her up and, as you say, into a sling or buggy to continue napping. That way, you will avoid most OT. I would continue to try to extend some naps - for me this was usually the afternoon naps, as LO1 would be asleep at the same time. I had to sit with LO2 and actually pat her as soon as she started to stir round 25/30 minutes. If she actually got to waking up, there was little chance of a resettle! Those days, I had nap 1 cot + sling if necessary, nap 2 cot + resettling, cat-nap always in sling or buggy.
Average A times for this age are somewhere around 1 hr 30-45 so I would come back down from 2 hrs.
Overall, my priority would be to make sure she got enough sleep, however that happened, rather than for her naps to be text book perfect. Some babies just are short nappers but by no means all. It's up to you: you might want to take a few days 'off', or a few weeks, or, as I did, one nap every day, more or less. Do what works for you and your LO. Just beware of creating any habits you can't live with - I could live with a baby napping in a sling, I couldn't live with feeding to sleep for every sleep, for example.
And bear in mind that every baby is different - so it isn't the second time around, it's the first time, with this baby!
Average A times- BOOKMARK ME!!