Give it more time :-) Patience is essential to any gardener, indoors or out.

Thank you! I'll keep tending it. I suppose some cuttings just need a little more time than others.

The mix looks rather wet. Maybe it needs a little less 'tending' ;-)

Thank you! I've heard Geraniums don't like wet feet. The flower box this cutting is in don't have a drainage system, so I can't be sure if it's too wet. Would you recommend trying to transplant it into a planter just to be safe? Or should I just let it stay where it is and hope it's not too wet?

I've replanted the sprout in a container with proper drainage. Hopefully that will help it grow!

Soil looks very wet. Pelargoniums (not Geraniums) don't like wet feet.

It looks to me like you have saved a baby that came from a bad home. The leaves are nice and healthy. I am not sure I would change any growing conditions because of that. It is just a healthy little plant, a top a long lanky stem. For me, since I had one propagation doing well, as you do, I know that even if this plant took off, I would tire of the look of that long stem, and whack it off to propagate, or I would try planting the whole stem below dirt, and see if it sprouted roots and took off that way. If it does grow as is, the weight of a healthy plant has me worried your stem will bend or snap. Nice perseverance!

Planting too soon in a large container will give your plant a large reservoir of water when you irrigate. The root uptake will not keep-up with the irrigation. The soil remains wet for too long. Re-pot into a much smaller container. By the way, it looks like the cutting area goes down to a old stem segment? This makes the shoot strike root more slowly. If it already did, then just re-pot it.