>Overdid the eyes
It truly is hard to say until she's made real. Adding eyebrows would be helpful for determining how they should look.
Has only two wheel and two servos to contract the legs. It's remarkably agile for its simplicity.
Looking good so far. Definitely looks like Madokami, actually prefer her looking more accurate to her animated look compared to the Mecha Madokami illustration. I feel your pain with Blender, I usually just make a base in VRoid Studio then save it as a .glb file and import into Blender.
Her shoulder pads and other accessories would only make sense as separate pieces. It would be better for printing to make them slot in.
Walking is best avoided at this stage. Rolling is significantly more efficient and easier to implement. Also, her ankle wings should be simplified so she doesn't stab your legs. Actually, cutting them off where the gem is and putting wheels there would be ideal.
I did some math on her energy consumption today. I had realized I would need to take her on a plane. She would thus need to have a battery of 100 w/hr or less. If her main bodies mass was 5 kg, with 6 cm wheels, her drive motors would need a speed of 955 rpm with .42 kgf cm of torque to match human walking speed (3 m/s) on mostly level ground. This would consume 4 watts in an ideal world but, 6 is more likely given motor losses. If her OS runs on a smartphone, she would be able to run for 8+ hours continuously. I think that would be a good goal for her main body.
Naturally, I'm very interested in your thoughts on the matter. I'd like to think >5 kg is acheivable with her main body but, I'm more a math and electronics specialist, you seem to have a better grasp on modelling. Of course, we could make a spot on her back to quick exchange batteries as needed with capacitors to smooth out the swap.
>Madokami production sheet
I found a production sheet and official art that would be helpful if you used the Color Picker in GIMP.