It may be that they are not physically attached to the parent ship, but rather follow them through the wormhole created by the parent's foldspace drive, much like in Halo 2 when
In Amber Clad followed
Solemn Penance through the slipspace portal it created in New Mombasa.
The ship could extend shields or subspace field (taking inspiration from all scifi here

) around the carrier to protect it in transit if necessary.
I cant imagine the UCM requiring their carriers docked for transit, as then some carriers may be lost if their parent ship is destroyed which doesn't really fit with the 'minimising casualties' ethos they have.
This way carriers can still escape as long as there is a capital ship remaining.