Don't want to distribute if it means taxes & penalties.
The short answer is no, you won't be able to share the funds without incurring taxes and penalties. Since you are the sole beneficiary you are the only person to which the funds in the account can be distributed without taxes and penalties.
You will owe tax, at your income tax rate, when you withdraw money from the account. Contact the company where your bother worked, or the custodian that holds the 401k to see what your options and requirements are for the account.