If your sister-, she would come.

conditional sentence - এর 2nd condition অনুযায়ী principle clause - এ subject + would /could /might + V1 থাকলে If clause - এ If + subject + V2 হবে। সুতরাং নিয়মানুযায়ী শূন্যস্থানে invited হবে।

The correct sentence is:

"If your sister were invited, she would come."

Explanation:

• The sentence is in the conditional form, specifically the second conditional, which is used to talk about hypothetical or unlikely situations.
• The structure for the second conditional is: If + subject + were + past participle, subject + would + base form of the verb.