I’m not sure what lily pads so I went with the largest which have around 7.069m² of surface area or 0.0000007069km² surface area.

Earth has a surface area of 510,064,472km²

After 120 days of doubling we have

6.64614x10³⁵ * 7.069x10^-6 = 4.6982Ex10³⁰

So you are correct but it’s also around 23x the surface area of the sun.

I think the lilypads might need to be smaller than an atomic nucleus? Someone check my math. But still larger than a Planck length, so it is fine.

they wouldn’t, but it’s not a real pond, and not real lily pads. i was going to say 20 but went for 120 to make the ratio more extreme, not to make it realistic.