Intersection of 2 circles is ok. It's done in the middle of the next image:
In the right there's used the node tool. The top node is dragged upwards and it's handles are turned for sharper angle.
Intersection converts circles to a Bezier curve (=path). Modifying its nodes, node handles, removing nodes and inserting more of them is just the basic skill in Inkscape and other vector drawing programs. It's as important as drawing your own curves with the Bezier curve tool (=also known as "the pen"). Do not skip practicing those skills.
With the pen you can draw a curve which divides your leaf. In the next image only a 2 click straight line is added (red) It could as well be a curved path:
In the middle the leaf is divided with the line by applying Path > Division. In the right the halves are colored differently.
I guess that soon after practicing a while with the pen you see that it gives to you a good freedom to draw solid looking shapes directly. You'll start to draw shapes that your job needs and use circles only, when circular forms or the geometric facts of circles really are needed. For example one draws the next 2 part leaf with the pen straight in the fly in a minute including possibly a fast fix of a border curvature with the node tool and coloring: