Egg Allergy in Baby - any info please

Our almost 9 month old has an egg allergy - egg yolk no less! We tried egg yolk and she projectile vomitted... Dr said it was an allergy.

Our 23 month old toddler has no allergies, although we have not done any nut products as my hubby's brother has a nut allergy. But he eats eggs, milk, seafood, etc.. all with no problem.

I have read everything I can on the Internet, but can't find answers to the below.

My big questions are:

Because she has an egg allergy, is she likely to be allergic to other things? How can we tell?

I have read that babies with egg allergy often have other allergies - like milk. She takes yogurt great, but we hven't tried cheese yet, and we aren't going to try milk until one year - should we wait on cheese and milk even longer?

I am breast feeding - should I stop eating egg? I have eaten egg throughout the pregnancy and breast feeding thus far with no problem, but now I am not sure if it is a good idea!

I read that some babies allergic to egg, are also allergic to chicken... so should we not introduce chicken (we planned to at one year)?

For protein this leaves me tofu and beans (with rice) and of course yogurt... without egg should I be doing other things? We were planning to start chicken at one year, but we hold off on red meat until 3 years for both kids.

When/How often do you 'test' with an egg to see if the allergy is gone - do I try at 18 months, 2 years, 3, years, etc...

Thanks so much.