I want to add a utility sink in our downstairs utility room. There is a bathroom adjacent to this room with shared wet wall. I wanted to ask the pros the proper way to tap into the existing sink supply and drain lines. It appears that to tie into the copper supply lines I need to add tees to branch off for the new supply. For the drain line, what is the correct way to connect the new sink drain to the line. Can I take off the current PVC elbow and replace it with a tee with the two sinks coming into either side of the tee, or do I have to extend the drain line out and route a new line to the vent above where the current drain line connects to the vent for proper venting. Maybe these diagrams will help, maybe not. Thanks in advance!
I
I
I
I Sink One
I---------I
I Sink Two
I

or

I
I
I
I---new vent connect--I
I I
I Sink One I
I---------I------------I---I
I Sink Two
I
I