- Create a married couple in CAS, either homo- or heterosexuell, your choice. Homo works better in terms of aspiration points, because in the next step you´ll have to adopt a kid which is often a well rewarded want for same-sex couples.

- Move your couple in a starter home, cheat them money if you have to.

- Play them according to their wants and aspiration, but be sure to adopt a child sometime during the first week.

- When the child arrives, your couple is in for an unpleasant surprise: The kid was severly neglected by his former family and never learned it´s toddler skills!
(That´s because adoptees´ memories are wiped, of course, but we´ll assume otherwise for the purpose of this challenge.)

- The couple promises to take good care of their new charge. Soon they realize that with a little work his/her condition can be mended.

Your child has the following handicaps:

Cannot walk
The child can stand up and move short distances.
The child can move 2 spaces and before sitting down or having to grab something (a person, balletdancing bar, large dog or similar), so you need to furnish your house accordingly.
There´s no limit on how long your child can remain standing in one place (though you may wish to issue the pose-command in order to avoid iddle walking around).
It´s actually not as hard as it might seem.

The child can go to school only if one parent drives it there.
Private school is recommended as private school students recieve bonus skill points. Assume it´s a special school for handicapped children. You must not use cheats/hacks to get your child into private school!

Cannot talk
Interactions involving speech are forbidden. You can meaningfully communicate via hugs, kisses and kicks, but not talk at all.
This is difficult to handle in group meals or similar activities. As a rule of thumb it´s okay if the child participates in group activities, just don´t overdo it.
The child can sing along (lalala) and understands everything said to him/her.

Cannot use potty
Simply do not use a toilet or bush ever. This will generate some nasty memories, but it´s far from life-threatening.

Fortunately your child is bright and willing to work to overcome his/her condition. This is how you can help him/her:
In order to train the needed skills the child has to max out the skill tied to the particular toddler skill
Cleaning for Potty training
Body for Walking (learning physiology for this purpose is strictly forbidden!)
Charisma for Talking (with the right equipment this is possible for children)

All training sessions must be supervised by an adult, preferably one of the parents.
If the adult has nothing to contribute to the action, have him/her freeze in a pose of your choice next to the child.

The sweet thing is, that the child´s handicap isn´t a physical one. He/She has fully working antomy and just needs to learn how to use it.
Rope jumping may be a bit too much in the beginning, but using a slide is perfectly okay.

You win if all three skills are learned before young adulthood.
You can also score bonus points of you excel in your training.

Scoring Suggestions:

Taught a cat or dog 2 commands 5 points
Excelled in the school theatre play 5 points
prequesite:
Learned to talk 10 points

Learned Physiology 10 points
Won a log rolling contest 5 points
prequesite:
Learned to use toilet 10 points

Learned any foreign dance 10 points (awarded only once)
Got into school soccer team 5 points
prequesite:
Learned to walk 10 points

Got into school band 5 points
no prequesite

Best friend with father 10 points
Best friend with mother 10 points

You are traumatized enough as it is, so you recieve negative points for any of the following occurences:
Witnessed a death, fire, burglary, repo-man or aspiration failure -5 each time
Died, caused a fire or went into aspiration failure -5 extra in addition to the witnessing points
Had first kiss or going steady rejected -5 each
Had no friend in his/her age category -10 points (apply once for child stage and once for teenager stage)
Never had a pet -5 points (teddybears or similar can substitute for pets of you don´t have the EP)

Thinking about it...sounds HARD!

I might attempt this for sims 3

sounds rough lol