MVP is likely a 3 person race right now:
1. Stewart: 22.9 points, 9.3 boards, 3.7 assists, 1.5 steals, 1.4 blocks, 46/37/85 shooting splits, team is #2 in the league (20-6)
2. Alyssa Thomas: 14.8 points, 10.2 rebounds, 8.2 assists, 1.8 steals, 46/-/69 shooting splits, team is #3 in league (19-7)
3. A'ja Wilson: 20.7 points, 9.5 rebounds, 2.0 assists, 1.3 steals, 2.3 blocks, 55/24/78 shooting splits, team is #1 in league (24-2)
You also could make a strong case for:
Jackie Young: 18.8 points, 3.9 rebounds, 3.6 assists, 1.5 steals, 54/47/82 shooting splits, team is #1 in league (24-2)
Kelsey Plum: 19.4 points, 2.6 rebounds, 4.2 assists, 0.9 steals, 51/38/91 shooting splits, team is #1 in league (24-2)
At this point I would lean Stewart just based on overall production and impact, though Wilson/Thomas are right there. Stewart I think is the best all around player, Wilson is the best player on potentially the best team in WNBA league history, and what Thomas is accomplishing and how she's leading her team is unparalleled. Honestly all 3 have numbers and overall impact that outperforms most MVPs from the last 5+ years. Wilson has won 2 MVPs and this might be her best year so far, yet she could finish as low as 3rd in the MVP race if the season ended today. Shows the quality of talent in the league.
Young/Plum could join the conversation, but Young has a tendency to fade into the background sometimes, and Plum started off slow (though she's been remarkably good as of late).