Hmmm.... are you an only child? If you are an only child there may be better alternatives.
The main objective in making a will is to decide how property will be divided upon death.
From what you have said, your Mom is still alive, so technically both of them should make a will.
If Dad dies alone all goes to Mom. If Mom dies alone all goes to Dad.
And if both die together then the properties usually goes to a percentage equivalent split between all the surviving children.
Without wills the process goes through the legal system and takes longer, costs money, and becomes "public."
And also without wills there are no specific directions or instructions that take place and if they wish to leave something to a favored grandchild, they would not be able to document those wishes without making a will.
If there are children under minor status (<18 years of age) who takes care of them?
Essentially without a will, the courts decide everything. Including selling all assets (family jewelry or whatever items that may be desirable to keep within the family // family photos) and taking out debts, fees and finally dividing up the proceeds between the surviving children.
There may also be living trusts or other trusts to consider. What happens if one or both your folks get very ill before death? What happens if they cannot make reasonable financial decisions? Powers of attorney?
Probate court essentially oversees the payment of any moneys owed to debtors before the inheritors get anything. Most "executors" of a will, will need to hire an attorney to "find" debtors and to insure that all debts are resolved before the will of the deceased is followed.
Depending on the way your folks have handled property in the past may also be of benefit in this regard. Property/assets held as "sole" owner or "tenants-in-common" are required to go through probate court.
But, listed beneficiaries take precedance over anything stated on a will. Thus, if your folks have you children listed on bank accounts, property, IRA accounts, etc. as beneficiaries, then these items may not need to go through probate. The laws vary from state-to-state and you should look at the specific laws with regard to the specifics in your state. Estate laws. Inheretance.
As a start, you should recommend to your folks that they designate beneficiaries on any asset they have. There's not usually any limit to the number of ways that assets can be split. Banks are very accommodating in this regard too. It's a lot easier to add beneficiaries on an account than it is to update a will.
How to approach it with them?
If their wishes about the things they have gathered means anything to them (wedding rings even), then they shouldn't want the court system to decide how these assets will be split up between the heirs, or force sale of everything such that there are more dollars to distribute to the lawyers.
Unfortunately the child(ren) has/have a whole lot of work to do when a parent passes on. With wills (folks wishes spelled out), there's a lot less frustration, costs and heartache for those survivors. Does any parent truly want to leave their family in chaos? No. But that can happen.
No "will" will have absolutely everything spelled out -- but they help considerably when properly done -- because it's written, you cannot deny that that was their wish.