I have one ex- colleague who is a slacker at my previous job.
She always comes late to work and goes back early before 5 pm.
My previous boss is ok with her attitude because she is flexible as long as her employee completes her work before deadline.

The problem is that I always help her to complete her task and she's very dependent on me to complete her work.
During my last week at my previous company, my ex colleague takes leave for one week because she just simply wants to take leave.

When I tell her to wait until I handover everything for her and teaches her to do anything that she doesn't understand, she just brushes me off and says she doesn't need that. She already understands everything.

So I left my job last week to start new job at new place this week. She keeps texting me during office hour if she doesn't understand something. At first I am ok with that since I try to help whatever necessary, but now she also invades my weekend and my sleep time to text me about work. She is also frustrated if I don't text her back immediately. I am so irritated now and I want to block her number, but my new workplace is currently having business deal with her company and we may work together again in the future.
What should I do?
Should I just ignore her text?

She always texts me how to arrange and prepare the documents that I used to do previously.
Even the silliest thing that she can think on herself also she feels like she needs to text me.
For example, if client doesn't reply what she needs to do. It's common sense if the client doesn't reply she just needs to update with them. Why need to ask me about that?
At first I am ok since she texts me only during weekdays, but now she also takes the opportunity to text me during weekend or after office hours.
It's so annoying that it invades my free time.
I can't ignore her because my current company has business deal with my previous company and we might cross path again in the future.

Already did that but she scolded me afterwards.
She's acting so entitled.