Answer:
She speaks too softly to be heard.
Step-by-step explanation:
To and too are homophones - words that have the same pronunciation but different meanings, origins, or spelling.
To is a preposition. It has many meanings and can be used in many contexts and constructions. Here, we will use it to connect these two sentences.
Too is an adverb. It also has several meanings, and the one used here is to an excessive degree (too softly).
The way these two sentences will be connected is: She speaks too softly to be heard.