My friend, let's call her L, is struggling with depression for 4 years. She had 4 suicide attempts before which she isolated herself from everyone and slept all day long. 

Since yesterday her phone is turned off and she won't respond to anyone's texts. I visited L but her mother told me that she wasn't home and has gone for a walk. Me, being stubborn, decided to find her. I check out a couple of her favorite places and found her in nearby town. I gave her sweets that I bought for her earlier and sat besides her in silence.
I knew that she takes long walks to avoid people so I didn't want to force any conversations. 
After 2 hours of wandering around the town L headed to her home. I walked her there and we parted ways. 

Her phone is still turned off. I don't know what should I do. Will visiting her today be fine or is it too much? Will it be too selfish and annoying? I don't want make her angry but I'm really worried. Her mental state was getting worse lately and I don't want to let her attempt again. 

What should I do? please give me some advice