Your daughter is old enough (barely) to learn three sounds for each vowel:
-Long Sounds: a- make, e- meet, i- like, o- nose, u- blue
-Short Sounds: a- cat, e- egg, i- big, o- hot, u- fun
-3rd Sounds: a- car/father, e- the/her, i- pizza/piano, o- do/moon, u- put/book
The sounds are typically listed in that order, but we use the short sounds most.
-'r' combos: ar- car, er/ir/ur- her/girl/purple, or- horse
1. Small words (or syllables) with one vowel are usually short sound. Small words with one vowel at the end are often long.
2. 'e' on the end is silent, but it tells us the other vowel has its long sound. (side)
3. When two vowels are together, there are several possibilities, but usually the second one is silent and the first one has its long sound.
When we see a word we don't know, we count the vowels. The number of vowels and their positions will tell us how many syllables there are. Break the word into syllables, apply the 3 rules above to each syllable as appropriate, and then put them back together to say the word.
As to the two 'th' and 'ea' pronunciations (and other similar challenges), they are just things she will have to learn. Treat them as matter-of-factly as you can. Don't 'teach' her that it's a problem. Many of the most commonly used English words are sight words: They don't follow the rules, we just have to learn them.
Student or Learner