RN needs advice- family history

It has recently come to light how extensive cancer is in my family. My mother has 8 siblings, 5 sisters (all of whom have cancer) and 3 brothers (one died when he was 2). Here is a breakdown of the cancer:

-2 of my mother's aunts- both died of breast cancer

My mother's sisters:
-Rita: recently diagnosed with breast cancer (in her 60's), double mastectomy. No cancer in the lymph nodes
-Alice: ovarian cancer, currently under treatment and cancer has not moved (late 60's)
-Kay: lung/throat/bone cancer, finished radiation a year ago. Just found out it is moved into her ribs, lymph nodes and other lung. Will start treatment again this week. Smoker (early 60's)
-Eileen: deceased from lung/throat cancer. Did 2 years of treatment, smoker for most of her life
-Patsy: deceased from lung cancer, also a smoker for most of her life

Cousins:
-Linda: who is Rita's (see above) daughter also diagnosed with breast cancer in both breasts with some lymph node involvement. Had double mastectomy in May and is undergoing treatment (in her 40's)
-Rachel: is Eileen's (see above) granddaughter, diagnosed with ovarian cancer in her 30's, currently under treatment (is very private, not sure how it is going)
-Koozi: multiple brain tumors (not sure etiology)

My mother and I are both in great health (though she has Diverticulitis and had a bowel resection a couple years ago), do not smoke, we both do our annual exams and monthly breast exams (we both have fairly large breasts). We recently went to see a women's health specialist in our area to show her our history and see what we should be doing. She recommended that all the women in our family have the HE4 and Ca125 tests done and to go see a geneticist to let us know our risks.

My question is to those who are familiar with these tests/oncology. I have heard that they are somewhat controversial and are not always accurate. I am 24 years old and my mom is 61. I understand that I would have to live with the results of these tests, so my question is do you think this is the right course of action. Is there anything else we should be doing? Thanks!

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