I hadalmost forgotten,: she has beautiful socks, inalso two -colors, tooed. I almost forgot: she has beautiful socks, also two-colored.

I had forgotten, —she has beautiful socks, in two colors, too. I had forgotten—she has beautiful socks in two colors, too.

Using "em dash" instead of coma and avoiding the second comma are stylistic choices. Most punctuation guides recommend avoiding run-on sentences, that is independent clauses connected only with a comma.

ItThis is a gladcalm and calmhappy sheep. This is a calm and happy sheep.

"calm and happy" is smoother but what you wrote is fine :-)

It is a gladcalm and calmhappy sheep. It is a calm and happy sheep.

Repeating "happy" at the end is a nice closure.

It is an internal happiness, for thaHer happiness is internal; it doesn't need a smile. Her happiness is internal; it doesn't need a smile.

Or.... It is an internal happiness, one that doesn't express itself in a smile

It is an internal happiness, for thatso she doesn't smile. It is an internal happiness, so she doesn't smile.

"For" meaning "because" sounds formal. With "for" it could be something like "It is an internal happiness; for that [reason] she doesn't smile."

She has a fashion piercing in anone ear and a cute cap in two -colorsed cap. She has a fashion piercing in one ear and a cute two-colored cap.

I'd probably just say, "colorful cap" so it would be smoother

She has a fashionable ear piercing in an ear and a cute cap in two colors. She has a fashionable ear piercing and a cute cap in two colors.

This sheep itdoes not hasve any problems, and. She lovinges everyone equally. This sheep does not have any problems. She loves everyone equally.

The two ideas are separate enough that I think separate sentences is more appropriate.

This sheep itdoes not hasve any problems, and lovinges everyone equally. This sheep does not have any problems, and loves everyone equally.