TBH, I'm a big fan of letting babies sleep for as long as they want. My 16-month-old usually has a 3-4 hour nap in the morning (she's been asleep since 9.30am) about 2 hours after she gets up. And she sometimes has an afternoon nap too 1.5 hours before she goes to bed which I'm sure no-one would recommend but works for her.

So I'd be tempted to let her have a longer morning nap if she wants to and then see what happens from there.

BTW, I found that going from 3 naps to 2 was a lot better for me as it gave me more chance to get out of the house. Otherwise, by the time I'd given her lunch she was ready for bed again and I don't really like taking her out when she's sleepy/asleep.