Fantastic gift that gives back fun!
Since your cruiser is a single speed (or 3 speed?), and unless you're very fit, it will not help you get up hilly roads efficiently. That's why the bikes with multiple gear shifters are necessary for many riders --beginners and expert.

As long as you know your bike's limitations, enjoy!

(I personally wouldn't buy a cruiser regardless of my age. I see cruiser as a "fashion" bike. But they are hip/cool with certain crowds. Strong cyclists do mount hills on single speed bikes but it's not for everyone. Doesn't give me the gearing range power for ascending difficult hills or going fast on flats. I'm not a strong person, so I need all the technical bike component help possible. I have two 24-speed bikes. 3rd bike is a 12-speed and definitely is limiting to me.)

DD: in this thread there's a small a photo of yours truly on bike. The bike fits me.
http://forums.teamestrogen.com/showthread.php?t=34449

There's only a slight bend in my knee when seated and foot on pedal. My arms a slightly bent, not ramrod straight, over-stretched. My upper body is close enough to the handlebar set without being overstrethed....which is a frequent problem for newbies.

Alot of people (including myself) when they haven't cycled for many years or are unfamiliar with a new/strange bike, will lower the seat just to be comfortable for a few yards. But sitting on your bike and your feet flat on ground, will result in sore knees, since it feel too tight in leg movement when you starting spinning the pedals. So raising the seat abit and perhaps adjusting the handlebar higher or closer to you, helps. However the bike should never be too big nor seat too high, that your upper body rocks back and forth side to side when cycling seated in saddle. A rocking cyclist who is pushing along on flat terrain, means the bike is too big/seat is too high.

When a cyclist becomes strong and fit, they find the need to raise their seat a tiny bit more to give themselves more spinning power. However, always mindful it never hurts one's knees, never overstretching arms or upper torso too much.

Remember an experienced older woman even at 70-80 yrs. should be cycling a 24 or 27-speed bike just to make the ride easier on herself because she is changing her gears throughout the whole ride. After all, she is not getting much stronger at that stage in life.