What I claim is the ornamental design for a window screen edge adapter, substantially as shown and described.
FIG. 1 is a rear perspective view of a window screen edge adapter in accordance with the present design.
FIG. 2 is a front perspective view for the adapter.
FIG. 3 is a right side view for the adapter.
FIG. 4 is a left side view for the adapter.
FIG. 5 is a rear view for the adapter.
FIG. 6 is a front view for the adapter.
FIG. 7 is a top plan view for the adapter; and,
FIG. 8 is a bottom view for the adapter.
The evenly-spaced broken lines depict the bounds of the Claim that form no part of the claimed design. The dot-dot-dash broken lines depict environment that forms no part of the claimed design.