No you are not able to do this. Alexa ‘listens’ for a wake word and then starts processing commands. I wanted to do the same for my father and the work round I used is to set up an Alexa routine called ‘Alexa, good morning’. Which contains the following commands: to say ‘good morning’ back; then to say what the day, date and time are; then to say what the weather is; and finally to send me a notification on my phone to say that dad is awake.
All I had to do was tell dad to say ‘Alexa, good morning’ first thing each morning and subsequently to check my phone each day for the resulting notification. He is a creature of habit so I expect a notification before my coffee break! I think the threat of me ‘dropping in’ if he forgets is enough to make sure he remembers!