Selling shares over the internet for most brokers is cheap, less than $10.
But why would you be doing this?
Free hand-outs won't teach much other than to do less and wait for more handouts.
Better a young adult learn to earn.
I've seen it with peers, where the parents "helped out" when no real emergency help was needed except to avoid some hardship. Thing about hardship is it really teaches a person values (like the time I did without a car for 6 months and had to bus to work).
The lack of hardship combined with free gifts/money from parents leads to a dependency, lack of motivation, not even bothering to look for a better job.
(one fella no work in 12 yrs, other fella does part-time security guard when parents too slow on the $$$).
However, if its to support a realistic new venture/business or to buy a home then it makes sense.
Maybe I'm just jealous my parents didn't buy me successive cars, help with tuition, or buy me a home....