"The small woman plays slowly."
Translation:La malgranda virino malrapide ludas.
You don't normally make a compound by adding an adjective to a noun, as there is no reason why the adjective shouldn't have its full form. So it is not correct to stick "malgranda" and "virino" together to form a compound. Having said this, there are some compounds formed of an adjective plus a noun, but then the compound has a specific meaning, e.g. "nov-edzino" = bride, as opposed to "nova edzino" = new wife.
If you think "malgranda virino" is too much of a mouthful, you can use the suffix -et- and say "virineto" which means exactly the same as "malgranda virino". The suffix -et- can become an adjective in its own right "eta", so you could also say "eta virino".
"Malrapida" (ending in -a) means "slow", and "malrapide" (ending in -e) means "slowly". But please note than in informal speech English speakers sometimes say "slow" when strictly speaking the word should be "slowly" (like "Put down your gun nice and slow"). This is fine in gangster films, but in Esperanto you can't get away with using an adjective when it should be an adverb.
Words ending in -a are adjectives, words ending in -e are adverbs. I know people often get confused particularly about adverbs, and in English it sometimes happens that people use an adjective when strictly speaking there should be an adverb. This could obviously lead to confusion when speaking Esperanto, in which the two categories are very clear and distinct. If you need more information about adjectives and adverbs, try these links: http://grammar.yourdictionary.com/parts-of-speech/adjectives/what-is-an-adjective.html and http://grammar.yourdictionary.com/parts-of-speech/adverbs/what-is-an-adverb.html.
No, it's not an adjective but an adverb, which ends in -e in Esperanto. Adjectives relate to nouns, adverbs relate to verbs. "Slowly" (malrapide) doesn't describe the woman herself, but the way she plays, in other words "malrapide " doesn't relate to the noun "virino", but to the verb "ludas".