You should only let a connection add you if she meets one or more of these requirements:
- You've worked or communicated with the person more than a handful of times, and you like her professional attitude and track record.
- You don't mind the connection tapping into your network.
- The person is someone you would feel comfortable reaching out to for networking purposes.
- She is someone you know in real life.
- You want to help her out.
- She is someone you respect and admire.
- Someone you trust has referred her to you.
Don't feel bad if you decline someone's request; it's something that happens often, and you're only hurting yourself if you weaken your network. Adding and accepting a LinkedIn request is a gesture of trust, and it should be made with careful consideration.