Chao Help

You could Buy the Heart Fruit,that's used to mate Chaos.

I think the Chao has to be at least a Year old to be able
To mate.

Yeah there should be a way to beat Crystal,my Chao was able
To beat Crystal. Though his Level were all at around 90.
Just keep giving your Chao Stuff to get it higher.

They will be able to mate at age 1, with a Fertility Fruit bought from the Black Market for 300 Rings. I suggest increasing these stats to beat Crystal;
Run, Power, Stamina
(Speed, Strength, Health)
That will give you an upper advantage. My chao is level 53 Stamina but his rank in Stamina is D :(. But he can withstand most hits.

An easier way to get Chao with flowers is by eating a fertility fruit(Heart Fruit) with Chao at least one year old. You can do it with baby Chao but try to give five of these. So you might need at least 3,000 Rings to do the second option.

If you have a Chao with all ranks at least B,you can defeat Crystal in about 3-5 seconds. Mainly you Speed,Strength,Defense and Health(Run,Power,Swim,and Stamina). Only one Chao of mine can do this pretty easily without breaking a sweat and can get victory unscathed. Hope this helps.