My most sincere condolences . . .
The funeral home can arrange for transport of your mother (there is no requirement for family to accompany the individual). You can then travel on any good fare you are able to get (I am assuming you are at the Spokane end).
Once you get to the other end, however, there are a number of ways to reduce costs and still throw a bang-up funeral. There is no need to feel guilty about setting up arrangements with an eye to your budget (if your mom hasn’t made pre-arrangements).
For example, for a viewing, you can rent a casket. She can actually be buried in a much less expensive casket.
If her desire was to be cremated, it is ridiculous to burn up a casket. The only requirement is that an individual be in a container to be placed in the retort (for the health and safety of the workers). They make an item called an air-tray that is perfect for this purpose (+/-$150). In this case you could then spend the money on a nicer urn if you wanted.
You can do the viewing with a rented casket followed by cremation with an air tray and save a great deal of money. You don’t have to use the guest book that they will try to sell you (Hallmark makes perfectly acceptable gift books for about 20% of the cost).
Most cities have a cremation and memorial society that has set fees for their services that are very reasonable. There seems to be one in Houston at http://www.millerfuneral.com/cremation_society.html
You can do a memorial service that you or other family host (without using the services of the funeral home) and save a lot of money.
If you want some additional cost savings for this, feel free to send me a comment and we can talk.