08:45 M arrives from 9 with greenery stick, drops and leaves
09:28 F at 9 ledge preening, lifting right toes
09:34 jumps to nest and rearranges some nesting material, broods facing 6
09:40 pivots to brood facing 5
Note: many raptors seem almost compulsive about nest building and maintenance.
To avoid people panicking about the welfare of either hawklet, I believe the smaller is just fine. Even at this age a hawklet can go at least a day without food. It is not always possible to see how much each hawklet is actually getting fed. If you can observe the throat area at times during the day you will often see a bulge (a full crop).
Other factors to consider: if the hawklets are as I suggest a F (older) and M (younger) they will eat relative to their size. Also being first hatched the older will be stronger and more aggressive about being fed. The adults will support this BUT in some cases make minor efforts to intervene if the aggression is too great. However, the younger hawklet also effects the level of aggression. If that hawklet doesn't submit to the older, dominant eyas then the level of aggression can escalate to the point of fratricide or siblicide (death of nest mate). This is a phase in the hawklet's lives (other raptors display this behavior as well but death is not common if there is adequate prey) and subsides greatly after the first few weeks.
From my experience I believe both hawklets are fine, the adults are providing for their needs and they are developing normally based on gender differences.
During the observations of this Redtail family you will occasionally view the birds standing on one set of toes (birds don't stand on their feet unless "laying down", incubating or brooding). This is done to allow for some rest of that leg's parts or to bring the non-feathered portion of the leg (tarsus and toes in Redtails) up into the protection afforded by the body plumage.

If you continue to think the way you've always thought then you will continue to get what you've always got, is that enough?