Sea serpent is a little bit thinner fabric than the others but seems to hold up well (my daughter has a monofin tail in it that gets a lot of use). Coral seas mermaid - beautiful handmade mermaid tails and costumes1. These are mermaid tail or tail/top set.
If you have a "finis mermaid" brand or similar fin it will fit. Adult supervision absolutely required if she plans to swim in it. Size chart at bottom of this page.These are long because feet need to be in "ankle" to use that monofin. Open at the bottom for walking.
Walking is in small steps - not good for distance walking. If used in water, mermaid tails are for strong swimmers only2.
Adult supervision absolutely required for swimming with mermaid tails3. Chlorine, salt and sun can fade fabric. Do not leave tails lying out in the sun as fabrics can fade3. Scooting/jumping/scraping fabric on concrete will wear it out more quickly4. Some fabric colors can bleed.Keep wet tails separate from other items. No need to ask first.
Coral seas wants happy mermaids.