I'm thinking of giving my daughter, whom will be 25 % Thai, the name Siranee. What is the proper Thai spelling of that name?

ศิราณี

Thank you!

ศิราณี

Is it correct that the first syllable is high/rising (as it is a short vowel it's just high, though formally rising?) and the second syllable is low?

The first syllable is high, the other two middle tone: sí-raa-nee

The first syllable is high, the other two middle tone: sí-raa-nee

It should be [L]si[M]raa[M]nii, so no.

Are you sure it's a low tone? I know ร can "carry" the sound, but isn't ร part of a new syllable and thus ศิ should be considered as a short vowel with a stop and then it is a high tone?

Are you sure it's a low tone? I know ร can "carry" the sound, but isn't ร part of a new syllable and thus ศิ should be considered as a short vowel with a stop and then it is a high tone?

Short vowel plus stop does not determine the tone. For low consonants the tone is then high, but for high and mid class consonants the tone is low. (The rare exceptions generally mark their exceptionality via a tone mark.)