There is no single node to do , however an automatic approach to adding foam around the edge of the (translucent only! will not work with opaque) water surface is by using a DepthFade node like (see image 1). outputs the results shown in image 2.
To make work with your own material, you want to replace the Red color lerp input (in the first image) with your foam texture. The second lerp & DepthFade is not necessary, but allows you to use a second foam texture to help blend even further (replace the Green color lerp input). Your original water material nodes would be plugged in to the first lerp where the blue color is connected.
Using technique I get the results shown in the final image (which it won’t let me post, giving me a database error… will upload it when I can). The reflection you mention is the real problem with using a translucent water shader at the moment, but is something Epic has said will be addressed in future updates by implementing Forward Rendering + Planar Reflections for translucent surfaces. Increasing the specular (to 1) and the metallic (to like 0.35) with a SkyLight present in the level will give you some basic sky color reflections, but to go further you would want to use a ReflectionVector node with a cubemap (either created live with a SceneCaptureCube, or texture) but it depends on your level setup. Also make sure you use TLM_Surface in the translucency settings of the material.
You can download the project linked below in my signature if you want to play around with , I left in the reflection vector node mentioned above for reference.