I rescued this plant back in August, and I noticed recently that its younger leaves have begun to curl under. I don't believe the plant is necessarily sick, but I am under the impression I am not fulfilling its needs. It's about three meters from a tall window (I moved it to take the picture), though I believe it only receives direct sun for maybe one to two hours in the morning, at most. I also water it very sparingly, in relatively small quantities. On average it probably gets watered one to three times a month. Is it possible that I'm underwatering it? Would that cause the leaves to do this?

I also am curious about the shape of my plant. My kalanchoe has always been kind of stalky like this since I got it, and I was wondering if it is healthy for the plant to be like this. Most kalanchoe I've seen are a lot fuller, and shorter. Is it recommended that I do something about this as well? I don't mind it's appearance being tall and stalky, so long as the plant is ok.

Any opinions/suggestions are much appreciated. I don't have the best luck with succulents, so I'd like to do my best to look out for this little guy.

That plant is not receiving anywhere near enough light. Plain and simple, its etiolated.

Your plant wants more light. It's different appearance you mentioned is a result of etoliating. Here is the definition:

Etiolation /iːtiəˈleɪʃən/ is a process in flowering plants grown in partial or complete absence of light. It is characterized by long, weak stems; smaller leaves due to longer internodes; and a pale yellow color (chlorosis).

This is likely the cause for you Kalanchoe having a different appearance as well.

Do you have a window with strong light available. If not, can you move the plants closer to the light they are in. I would get it within a foot if possible. When your weather is warm enough for it to go outside after the last frost, it will reward you with lots of normal growth. Inside these plants want the brightest light, but outside they both want the brightest outdoor spot that is protected from full sun. It's too hot for them.

There are experts here who grow your plants and will come along and give you good advice. Good luck.

Alright, thank you for your responses. I'm guessing it wasn't getting adequate light even before I got it, then, because it has always been like this. Anyhow, I don't have as many good plant spots as I used to but I currently have a folding table set up in the box window (east-facing) that I can probably relocate it to for the time being.