Every child is different, so it's always hard to know exactly why babies do what they do! A couple ideas for her behaviour you could consider is:

a) Noise - being your second child, there is probably a lot more noise going on while she is feeding. If so, you could try going into a different room where it is quieter and see if it makes any difference.

b) Stronger let down - you might be pumping the milk faster than she can drink, so she breaks away to breath/swallow before returning to the breast again. Not sure what to try if this is an issue.

c) Gas or reflux issues - if her tummy is sore, she will be squirmy. Does is make any difference to her behaviour if she is having the first or second side? I can only feed my son one side at a time during the day or he becomes a squirmer. Holding him to feed more upright (e.g. I sit cross legged on the bed and have him sitting on the bed between my legs feeding in a more sitting position than sideways) does help me a lot with his feeding.

d) Cool stuff going on - if the rest of the world is simply too interesting she might be pulling away to not miss out on what is going on. You could try covering her with a shawl or something to block out the interesting sights and keep her focus on feeding and see if it makes any difference.

10 minutes a side is a fairly normal length of time to take for feeds, so it that is how long she is taking it's not uncommon all up. Boys do tend to drink faster on average, but again comes down to personality!

Hope any of this helps!