Final answer:
The correct word to complete the sentence is 'hablando'. It is the gerund form of the verb 'hablar' which means 'to speak'.
Step-by-step explanation:
The correct word to complete the sentence is hablando.
'Hablando' is the gerund form of the verb 'hablar' which means 'to speak'. In this sentence, 'Mi suegra está hablando de mi' means 'My mother-in-law is speaking about me'.
Other options like 'habló', 'hablaste', and 'hablamos' do not fit in this sentence because they are different verb forms that do not match with 'está', which is the form of the verb 'estar' used here.
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