Completely agree with others - if she's relaxed and happy with her day sleeps don't worry about it. my 4 month old is completely unpredictable. sometimes she'll do 4 lots of 45 mins sleeps in the day, sometimes she'll do a longer sleep say 1.5 hrs then another couple of shorter sleeps.

The easiest ways i've found to resettle to sleep (if she's looking like she needs more) are feeding or popping in a sling but generally if she's not back to sleep within 20 mins, I stop trying. Your DD is having great sleeps at night at the moment which may or may not change soon - a lot of babies start waking around the 3 month stage as there's a lot of developmental stuff happening so i'd say enjoy the sleep and go with the flow.