5.30am wake ups and back to am naps? help


My 16 mobth old baby used to nap twice a day: once in the am and once in pm. bed 7.30pm. a month ago she started sleeping until 7 -7.30 am and once she did that, she stopped her am naps and was sleeping in the afternoon (one or two naps). For the past 2 weeks however she's been waking up at 5.30 and because of this she wants to nap at 9am and 12 and again at 3pm. she stopped napping 3 times a day months and months ago. I don't know what to do. she's had a small cold for about 10 days. Is this a phase ? a regression ? it doesn't seem linked to her cold so I have no idea. it's so difficult to plan the day and get her "ready" for her naps because i never know when thet will be. any ideas ? advice ? thanks