21 mo won't go to sleep at bedtime (chatting instead!)

[mummingbird]

My 21 mo dd has 45min-1 hr nap in the afternoon between 2pm and 3pm.
When I put her to bed at 7:30 after her usual milk/bath/story she sits in her cot chatting for up to an hr and half! (sometimes she calls 'mummy' or whimpers a little but normally not too much complaining). This has been going on for about 3 wks.
How can I get her to go straight to sleep?
Shall I cut out nap and try to string her out until bedtime?
(if it is relevant: she wakes about 7am with no waking in between)
Hope someone can help... thank you for reading.

My DD is the same. It bothered me for a bit, but now I think, well, she's not crying, it's not making her overtired in the day, in fact, it means she always has at least an hour's nap which means I can too (have a newborn), so I just let her chat.

DD1 was the same, still tell story to herself if not to tired at 6 yo. It stopped for a while when she dropped the nap.
Just let her to it. Why does it bother you?