Long naps

My girl has just started having 3-4 hour afternoon naps the last couple of weeks, waking between 5 and 6pm, totally killing normal bedtime routine. When she naps this long she goes to bed between 9 and 10am (waking between 6 and 7am, which is normal time).

I’ve tried making her nap earlier but it’s such a battle, she doesn’t seem tired enough. So I gave up on that as it was just not happening. I would end up battling with her for an hour and then she’d end up napping same time anyway.

I woke her up today at 4:30pm and we came out to the sofa and she curled up and went to sleep again - even with her 9 month old brother playing loudly on the floor next to her!

It’s now 5:10pm and I dunno whether to wake her again.

Any advice? Just a phase, should I ride it out? Or start waking her? Part of me is kind of enjoying the down time in the afternoon.