broodies are defeintly funny creatures, I had 2 broody chickens at one time, they both had eggs, but one set did not hatch (they were both due on same day) she buddy up with the other mom who hatched out 4 and they shared the responsiblity for them. So if the 2nd one wants to sit, you can let her and she may be able to share the responsibilty especially since the other mom does not mind her next to her.
but if you do not want to let her sit, you can keep taking her off nest put her in a open bottom wired pen and in a couple days that should get her out of broody mood