Certified GKH Gardening Expert
The more light you can give the tree, the more likely the flowers will be to develop and produce fruit. If your window area doesn't provide full sun, consider adding a grow light. Be sure not to overwater the tree, but only water when needed, because it will use less water during the winter. It will take about 6 to 9 months for the buds to develop to ripe fruit.
Here is more advice on Meyer lemon care: