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

Yes

The word "senhora" is identical in meaning, grammar, and spelling in both Brazilian and Continental Portuguese. The only difference lies in pronunciation.

In Brazilian Portuguese, the vowels are generally more open and clearly articulated. The "e" in the first syllable is pronounced clearly, and the final "a" is a distinct, audible vowel. In Continental Portuguese, the pronunciation is more "closed." Unstressed vowels are often reduced or "swallowed" (a process called vowel reduction). Consequently, the "e" in "senhora" may sound more like a short, closed "i" or even disappear, and the final "a" is often whispered or extremely short.

Brazilian Portuguese Examples

1. A senhora gostaria de um café? (Would you like a coffee?)
2. A senhora viu o meu celular? (Did you see my cell phone?)
3. Como a senhora está hoje? (How are you today?)
4. A senhora é muito gentil. (You are very kind.)
5. Boa tarde, senhora. (Good afternoon, ma'am.)

Portuguese (Continental) Examples

1. A senhora gostaria de um café? (Would you like a coffee?)
2. A senhora viu o meu telemóvel? (Did you see my mobile phone?)
3. A senhora encontra-se bem? (Are you well?)
4. A senhora é muito gentil. (You are very kind.)
5. Boa tarde, senhora. (Good afternoon, ma'am.)