Having coached Judo to Juniors over the past 30 years.  I have found that there are very different approaches to how we can get the message from Professor Kano across to our young Judoka.
Kano’s view of Judo was quite clear.

It was to be a good source of fitness, fun and discipline, rolled into a sport which could be enjoyed safely for all ages.

With it roots in Ju-Jit-Su or ( Ju-Jut-Su) as a fighting Art, we find an easy cross over into Kano’s Judo.

Fundamental skills can be used as a platform to good commonsense Judo.
Taught, in stages. Judo is a positive, progressive sport.  Grades are awarded as the Judoka acquires greater skills.

Interactive skill games are a good tool when teaching the young.

Games Make Judo lessons informative and fun.

These include, Team Work, Responsibility and physical contact, with other Judoka.  
They can also help the young Judoka to learn some simple Japanese Judo language.  Such as counting, Colours and Body Parts.  All of which will be useful as they grow into older Judoka.

Sometimes, children arrive with a degree of timidity.  This can be attributed to being interested in trying something new. (But not really knowing what to expect) Meeting new friends and having new experiences.

As young Judoka, Judo can help to develop a more confident character.  This is not a speedy process.  But can be achieved by gently introducing recognisable skills that they may have seen in PE lessons at school.  Tumbles, Jumps and use of equipment.  (Crash Mat, Hoops, Bean Bags, rubber balls) ect.

The practice of Ne-Waza (Groundwork) Judo.  Can be a great asset to use, when teaching a timid Judoka.  Here there is no throwing requirement and can be developed into Tachi-waza (Standing Judo) as their confidence and interaction grows.

Most young Judoka, arrive with a pre-conceived idea of what they think Judo is.  The Internet/Television/film industry contribute greatly to how “Martial Arts” are represented.

Martial Artists are portrayed as the full range.  From Hero’s to Villain’s.  Funny and fearsome.  Young Judoka often have an idea of who they would most identify with.  This is not a bad thing.  As it shows that they have thought about the persona that appeals to them.
Judo is not a Martial Art. It was declassified in 1960’s to allow it to become an Olympic Sport.
Competition Judo is another facet to Junior Judo.  Judoka as young as five years old can take part in “MINI Mons and Red Belt Rumbles”.  This competition is generally only at club level and used as an introduction to competitive Judo.

Junior Competition, at a higher level - can usually be expected to be entered into at an average age of  9/10 years.
By this age the Judoka’s grade should be rising and competitive skills beginning to be developed further.

When I am asked “Will my child like Judo”?  I can only suggest that they try a couple of lessons.