This would make sense because my LO is coming off of a stent of short naps, and has trouble with the last nap of the day. Here's yesterday's schedule...
6:30 AM Awake, Eat
7:10 In bed, asleep at 7:30
9:00 Awake, Activity
9:30 Eat, Activity
10:00 In bed, asleep at 10:15
11:15 Awake, Activity
12:00 Eat
12:15 In bed, asleep at 12:20
3:30 Awake, Eat
4:40 In bed, talked/whined on and off with maybe 2 10 min catnaps until 5:30
5:30 Eat, Bath
6:20 In bed, asleep by 6:30
7:30 PM Awake, crying
(Took me until 9:15 when I eventually fed her to get her back to sleep)
10:30 PM Dream feed
3:45 AM Awake, gave paci, rocked for 2 min, back asleep, in bed with me (bad habit, I know!)
6:40 AM Awake, Eat
It seems to me that when her first 3 naps are decent, she has trouble taking the last one. SO I think she's getting overtired at the end of the day (like you said) and maybe having trouble staying asleep at night time.
What do you think???
Thanks, Amanda