Okay, while posting the above I noticed three more errors and a minor inconsistency in the D&D Beyond Versions.
Firstly, the Rhagodessa ought to have "
Hit: 9 (2d6 + 2)", somehow I failed to notice it's average damage shouldn't be 8 as far back as the
Medium Rhagodessa!
Secondly, their Perception +2 and Passive Perception 13 don't match up.
They should either have +3 and 13 or +2 and 12. No idea how I missed that one!
Now, the usual "rule of thumb" is creatures that are extra-proficient at skills get twice their Proficiency Bonus, which is why the Giant Spider has Stealth +7 (from its Dex +3 and another +4 from twice its +2 Proficiency Bonus), so I'd go for +3 and 13.
Thirdly, the Flyweight has Stealth +3 just from its Dex, if it's proficient it should have +5.
So I would change it to:
Flyweight
Skills Perception +3, Stealth +5
Senses blindsight 60 ft., Passive Perception 13
Giant & Rhagodessa
Skills Perception +3
Senses blindsight 60 ft., Passive Perception 13
Finally, I only just noticed that the Giant version has Int 2 while the two Medium sized ones have Int 3. They both give the same ability modifier, so I'm wondering why the incongruity. Shouldn't they all have the same Intelligence, probably 2 like the Giant Solifugid, since I haven't seen any folklore portraying Solifugids as "cunning" like a Spider (which I guess is why Giant Spiders have Int 3 in 5E, although that's still way inferior to the Intelligence of 5 to 7 they had in AD&D)
Personally, I prefer Int 1 (−5) like a Giant Scorpion, but it's your conversion.
Apologies for not noticing these issues before you posted them on D&D Beyond.