hello my dd has been waking up twice in the ni...

hello my dd has been waking up twice in the night for about four out of six nights now, goes to bed at around 7.30pm then wakes up at 12.30pm then again at 3.30pm, then at 6.00am. How long do the growth spurts last approx? she usually goes to bed at 7.30pm and wakes up around 2-4am...