Hi Martina,
I'm a mom of 2 girls 7 and 11 and the youngest one's name is Martina. I love that name. I know it must be a big adjustment to be at home instead of working. Try to find out the routine that the daycare followed and perhaps copy a few of their ideas. Experts say the first 5 years are critical in the developement of a child. You could write down an informal scheduale for things you could do together. You're lucky that she an only child so you can give her alot more attention. I personally don't mind letting the housework slide a little and spend more time with her. I'll give you some ideas what i've done with my girls.
1. go to the park
2. get art supplies and make things together.
3. library
4. read to her every day - sing songs.
5. make some play dates and involve the mom's
6. learn to play with her on her level -play hide and go seek etc
7. do her nails and make a pretend spa day
8. buy some board games and play with her. (teaches good sportsmanship)
9. let her help you bake some cookies.
10. get her involved in some community play groups (they're in-expensive) and it will help her prepare for school socially. She most likely misses the interaction with the other children.
11. talk to her alot.
12. get her some playdo (you can make it yourself) and play with her.
13 Take her for swiming lessons.
These are just a few suggestions of thing you can do. I think it's great that you want to do all you can for her. Cherish this time you have with her, because it goes so fast. You probably are feeling down because you lost your job, but instead look at, as a blessing that you can share so much time with her. You can form a bond to last a lifetime.