They are technically the same "family", as in genus. The same way a pointsettia is related to a Candlelabra cactus (both are Euphorbia genus).
See here:
https://gesneriads.info/gesner...
Scroll to the bottom and click on all these Streptocarpus types:
-- Streptocarpus section saintpaulia
-- Streptocarpus subgenus streptocarpella
--Streptocarpus subgenus streptocarpus
