Can Neon Tetras, Red-Eye Tetras, Fruit Tetras, Stripe Fish and Guppies live together in the same tank?

My sister just bought 2 Guppies and 3 Neon Tetras. Right now, her tank isn't set up yet (she got carried away with the fish thing and bought the fish before the tank was set.) I have Fruit Tetras, Stripe Fish, and Red-Eyed Tetras in my tank with a Plecostomus. Can I temporarily put the Guppies and Neons in my tank? Or should I have a divider or a separate larger net in my tank for the Guppies and Neons instead?