Thank you for your question.
Your proposed plan of action does not violate any California criminal law. There could be a civil dispute that arises regarding whether you have "converted" her personal property which is stored in your storage unit. However, you could argue that you have a lien on the property for unpaid rent.
It would be advisable to go ahead and post an Eviction notice on her front door. It is a 3 day notice. The exact contents of the notice are covered at CCP Section 1161(2). The notice must include a demand for the precise amount due, with instructions on where to pay it, an unequivocal demand for possession
if the rent is not paid within three days of service of the notice, the date of the notice and the signature of the landlord or an agent for the landlord. The notice may be served, either:
1. By delivering a copy to the tenant personally; or,
2. If he or she is absent from his or her place of residence, and from his or her usual place of business, by leaving a copy with some person of suitable age and discretion at either place, and sending a copy through the mail addressed to the tenant at his or her place of residence; or,
3. If such place of residence and business can not be ascertained, or a person of suitable age or discretion there can not be found, then by affixing a copy in a conspicuous place on the property, and also delivering a copy to a person there residing, if such person can be found; and also sending a copy through the mail addressed to the tenant at the place where the property is situated. Service upon a subtenant may be made in the same manner.
After she doesn't pay, file the eviction proceeding.
In short, you have a good plan and should proceed, but you should also file the eviction.
Please let me know if you have further questions on this topic.