Wills and Estates

How can my sister and I be beneficiaries of our grandmother's estate?
My grandmother passed away in the 90's. My mom passed away in 2001. My sister and I recieve financial statements for my grandmother. My sister was my grandmothers power of attorney. My grandmother lived in Texas until she moved in with my sister in Colorado till she passed away. Her house was destroyed in a tornado, recorded. There is not any paperwork anywhere. How can my sister or me be determined to be an estate beneficiary to my grandmothers funds. In other words, how can we get our money, there isn't anyone else.
Does separate property pass according to a will after one spouse dies?
Is the separate property as opposed to joint property of a marriage disbursed as per a will on death of one party?
How can we ensure our children inherit after both spouses die?
If my husband and I have a will leaving everything that we own to each other, and we both have children form a previous marriage, how can we make sure that the children of the last one of us living will get their portion when we die? Example--My husband dies, I own everything, then I die. Since I owned everything when I died what would assure that his children would get his portion what was left?
What type of will should a remarried widow with children create?
I am a remarried widow with 3 children ( ages 11 and 9 yr old twins). I have assets from my 1st husbands death that I need to keep seporate from my new husband and his children. I recieve pensions and benefits, so my husband and I keep our finances seperate. What kind of will do I need? There is not a widow-remarried in your choices.
Do we need a will or trust for our minor children?
Which legal documents do we need? (will or trust?) Please be as specific as possible. We are unsure if we need a trust since we do not own a home. 1) We have children who are minors and need to make sure their guardians are chosen and stated. 2)We do not own a home and have no significant assets at this time. 3)We would like to state our medical wishes. 4)Matthew is the sole beneficiary for his aunt and uncle's estate and business. 5)Matthew hold interest in his father's business.