Is the word pequena the same in Brazilian and European Portuguese?

Yes

The word "pequena" is identical in spelling, meaning, and grammatical function in both Brazilian and Continental Portuguese. The only difference is pronunciation. In Brazilian Portuguese, the vowels are generally more "open" and clearly articulated. In Continental Portuguese, vowels—especially unstressed ones—tend to be more "closed" or reduced, which can make the word sound more clipped or even slightly swallowed compared to the more rhythmic Brazilian pronunciation.

Brazilian Portuguese Examples

1. A menina é muito pequena. (The girl is very small.)
2. Eu moro em uma casa pequena. (I live in a small house.)
3. Essa blusa é pequena demais para mim. (This blouse is too small for me.)
4. Ela é a minha irmã pequena. (She is my little sister.)
5. Tivemos uma pequena confusão ontem. (We had a small confusion/argument yesterday.)

Continental Portuguese Examples

1. A miúda é muito pequena. (The girl/kid is very small.)
2. Eu moro numa casa pequena. (I live in a small house.)
3. Essa camisola é pequena demais para mim. (This sweater/shirt is too small for me.)
4. Ela é a minha irmã pequena. (She is my little sister.)
5. Tivemos uma pequena confusão ontem. (We had a small confusion/argument yesterday.)