Under the water

How old are you???

Soon Riley dived, she felt her lungs grasping for air for one last breath. She turned around to see the mermaids and to give them a signal that she can't breathe. Then soon they saw the signal, lily and Rebecca grabbed her wrists and rushed her up to the surface in a hurry.
Riley gasped as she went up," um... So how do I do this?"
" you breathe through your nose try it," Rebecca said
" ok," Riley said softly
Riley inhaled and exhaled then dived into the water at the same time as she splashed her tail at the mermaids, making them more soaked. she then tried the breathing technique through her nose but she couldn't, it felt like ice tea went up her nose it felt uncomfortable to swim with so she headed back up to the surface to report the news to the mermaids.
" I can't do it, it's too uncomfortable," Riley stated
" it's ok if it's uncomfortable, you will get use to it," daphne said" I even had to get use to it when I was a young mermaid like you"
" wow, I know it's rude to ask but... How old are you???" Riley asked
" 479 years old," Rebecca replied
" 109 years old," lily responded
"599 years old," daphne frowned
" oh my god, you look like your in your 20s!!!" Riley exclaimed
" probably because we've been in are 20s awhile," lily shuddered slowly
" but we're you young... Well you know when you were a small mermaid if it's possible???" Riley said
" yes we turn into adults when we're 102 years old, lily here turned adult a few years ago," daphne replied
" ok... but when do you turn like... Turn Elderly???" Riley replied back
" when your 610 years old," lily said
" wow..." Riley froze
" ok that's enough questions, we have some swimming to do, to go see your real father, the king," Rebecca explained
" do we have to???" Riley asked
" yes!!! You have to see your father and most especially the kingdom, come on let's embark on this about to be amazing adventure!!!" Daphne exclaimed
" fine," Riley said.