It looks to me that she's waking after each sleep cycle. If she's handling it well (that is going easily back to sleep) it's likely she'll grow out of it. Although each lo takes their own time so she might do this for a couple of more weeks or maybe a month, who knows? If it doesn't escalate to waking early from the nap or too much intervention on your side, leave her be.
Another reason of waking at the end of sleep cycles might be overtiredness, which leads me to your second question. As much as you want to preserve a nap time, your dd is still young and her daily routine should be lead more by her cues rather than a rigid schedule. That is, if she woke as early as 615 am she's probably to feel (and start showing sings of it) tired around noon. If so, she shouldn't be in bed later than 1215/1230 tops. The majority of young toddlers don't do well on activity periods longer than 6 hours (of course, there's always one or many exceptions) and if you push them too far, overtiredness gets in the mix causing night wakings,s hort naps or interrupted sleep cycles.
HTH!