Kindermenüs - why the s?

From 18.3 Going out to lunch - Extra Vocab. According to the Leo dictionary,  Kindermenüs is the plural form of Kindermenü, also Menü - Menüs.
Wouldn't it be better to give the singular form with the article?

As a supplementary question, what about the genitive in nouns that end in s in the plural? Can they have an s in the genitive singular?

Hi sfpugh, 

yes, the correct translation should be "das Kindermenü" - "the kids' menu".
I will pass this on to get changed. 

The declension of das Menü in singular and plural in the genitive case would be:

"des Menüs" (singular) - "of the menu"
"der Menüs" (plural) - "of the menus"

Other examples of nouns in the genitive case which end in s in the plural would be:
"des Autos"  (neuter) - "of the car"
"der Autos "  - "of the cars"

"des Opas"  (masculine) -"of the grandpa"
"der Opas" - "of the grandpas"

"der Oma"  (feminine) -"of the grandma"
"der Omas"  - "of the grandmas"

Let me know if you have any further questions!

Grüße
Julia

Thank you for the explanation.
So Kindermenüs is ambiguous without the article. It could be genitive singular or any case plural.