It doesn't take a large investment to make extra money at home.
You just have to have a great idea and know enough about marketing to get your business idea off the ground.
The whole point of marketing is deliver a product in demand to a valid market.
Just as a farmer goes to town to deliver their fresh produce, the basic principle is the same.
In this day and age you don't need to hide the fact that you have a home office.
You can still maintain a professional image with business cards and letterhead.
If you prefer not to use your home to conduct your workshops, then find a church hall or other location that you can use.
Add some professional credibility to your business by teaming up with an already established business (childcare center, Gymboree etc.
and offering classes or free informational seminars at their location.
While you may not have a professional degree in teaching a baby to sign, keep in mind that you know much, much more than most people.
You can teach others or find a service to offer.
Don't apologize or explain.
Give yourself the title of whatever the business is that you choose on your business cards and letterhead.
Come up with a creative yet professional name for your business.
If asked, say that you have been trained by a certified speech and language therapist.
The more you talk and the more speaking credentials you build, the more you will be regarded as an expert.