How much are you watering?

I water very little only between the months of June and October. I have a basin located off to the left of the photo to water the queen palm. I'm not sure that the aloe's roots can reach the basin since it's about 5 feet away. It's really plump from the last couple of rains

If its planted deep enough and the roots are well developed it should not be an issue, its a 'single stem or sometimes called tree aloe".

It shouldn't be top-heavy, unless the roots haven't developed commensurate with the growth of the plant. At any rate....

Stake it - three of them with some firm-but-not-tight staying ropes/wire (wrapped by old garden hose, naturally) - will do the trick.

Thanks for the tips guys/gals! These aloes are getting to be a nice size, I'd hate to have one topple over.

Aloe marlothiis are well known for falling over here in Southern California, but usually it's due to poor roots (over watering) or high winds. Recent wind storm in Pasadena knocked over a LOT of tree aloes at the Huntington Gardens, including half of a 30' tall Aloe barberae. Garden is partially closed for a long time now to clean up all the fallen trees.

The good thing about fallen Aloe marlothiis is they seem to take rerooting well.

Mine was in a pot. The head of mine was too big for the stem to support so it bent over. Roots had already formed above the break in the stem so I cut below the roots and repotted. The sides of the new pot support the head while the roots get going. I think I posted the whole sad story with pix here a few months back.
It looks unfazed by the experience.
Geez, it's always something!

Had the same thing happen to my ferox, I was told to quit cleaning off the dead leaves as that is what helps stabilize the plant as it grows.