United MileagePlus (Consolidated) - Changing flight on new website - split PNR before seeing possibilities?

I possible need to change my return flight on an existing reservation but I'm traveling with my parents.

When I go to do a change it tells me that the reservation will be split into separate PNR's. I don't want to split it until I know what the potential change fees are.

Will it split the PNRs BEFORE it allows me to just see what my options are?

Thanks!