Leela's parents have appeared in mutant crowd scenes in previous episodes.
Baby Leela's alien language blanket-pinned note translates to: Your Parents Love You Very Much
The only episode of Futurama to be rated "U" (Universal: Suitable for all) by the BBFC. All other episodes are either rated "PG" (Parental guidance) or "12" (not suitable for anyone under the age of 12).