[AquaA]

I know that feeling too well my family actually refers to me as the flat one since they're all huge in comparison. Even now that I've gained weight they still tell that "I'm small but it's okay you've got a hot butt" :/
Use this as motivation, you will reach your goals one day and your boobs will be perky and beautiful while theirs will give off to gravity since they're probably not taking good care of it.
Plus your boobs are already beautiful! Shape beats size any day so you don't really know how things look for them without all that support.