Maybe its time to move to one nap?
My DD (also 14 months) seems to have a quota of about 12-12.5 hrs sleep in a 24 hr period that she keeps to - if she sleeps more during the day then she sometimes has less at night - like wakes up early, or wakes during the night and takes 1-2 hrs to go back to sleep

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I guess all you can do is experiment