There are many plants, but some are only single stems :) she will need to grow them out herself. most of these are moderately fast growing plants, but will build a good collection of different plants for her ^____^
Large floater, fast growing, will help filter water with it's feathery roots. A trye aquatic grass
Frogbit/Dwarf water lettuce/ salvinia/ duckweed:
Floaters, fast growing helps process nutrients but may block out light. Throw out/ give away as needed.
Java moss: a rather stringy moss, medium slow growth (might have other moss mixed in)
Susswassertang: A fern gametophyte, slow growth, can be left floating or attached to something.
Java Feen Trident: When mature, tips of leaves split into three, hence "trident"
Crypt: Hardy plant, medium growth, expect melting due to disturbed roots
Myriophyllum Mattogrossense: fast growing stem plant, really pretty plant
Cardamine Lyrata: Another fast growing stem plant, very nice if tied to the hardscape.
Water wisteria: fast growing stem, I'm sure we all kniw wht this is...
Saggittaria: Long grass like leaves, can surprise you with sudden bursts of growth.
Ludwigia/Rotala: fast growth, Not sure which one, dont ask.... but is pretty and red when given high light.
Microsword: tiny grass like plant, slow growth in low light.
Guppy grass: An extremely fast growing weed like stem plant. best grown bunched (when it does grow out)
Giant baby tear: Not really a hard plant to keep, beautifuly light green an delicate leaves. loves light, best left floating if tank does not have enough light.