Yes, have seen it before. It does not mean anything.
I have seen 3 finger first leaves, 5 finger second leaves, 4 finger leaves, 2 finger leaves, 13 finger leaves, - you name it.
Each plant is an organic, living, individual being, not a machine made item of absolute perfection.
No plant will ever have 100% perfect leaves, 100% of the time.
The third set of your leaves look like they will be 5 bladed, so as long as she keeps growing, there is nothing to worry about.