Correct time between antibiotic use?

My child (age 2) was diagnosed with Pneumonia.

she is to take 5mg antibiotics 3 x a day,

Now I usually give it to her in the morning, afternoon, night, she sleeps 12 hours at night though, and her wake up time is not predictable with her cold.

it goes like:

630am, noon, 630pm OR 730am, noon, 730pm... so she is getting 12 hours throughout the night with no antibiotic, should I be spacing the doses better? the doctor and pharmacist didnt say about how many hours in between or how to space them?

Yesterday it was 730am , noon, 730pm, then she didnt wake up till today at 10am..

so I gave her meds at 10am, Im not going to give them at noon because that would be 2 hours later, should I just give them x2 today morning and night, or should I try to space 6 hours and give in middle of night?