
Sorry for your loss :( clearing out her flat is going to be nostalgic for you. You will find things that will make you laugh and cry.
I cleared out my grandmothers house when she died, back in 1998 and I spent 2 weeks there, her house was like the old curiosity shop so it took that long. But I found things that I had forgotten about and also little momento's that I kept. I still get them out occasionally and indulge myself.
Good luck, it's not easy and alway sad, My Gran was 77 and everybody said , well at least she had a good innings. That's not the point, the point is, whenever anybody dies, however young or old, you will always miss them. My gran virtually brought me up.